Being in a frisky mood may improve your chances in the dating world
Positive, romantic thoughts could produce positive, romantic outcomes while dating.
25 September, 2020
Credit: 4 PM production on Shutterstock
- Fear of rejection, self-doubt, and anxiety are just some of the obstacles humans need to overcome to make a meaningful, romantic connection with another person.
- According to a 2020 project by a group of psychologists at the University of Rochester (and the Israeli-based Interdisciplinary Center Herzliya), humans see possible romantic partners as a lot more attractive if they go into the interaction with a "sexy mindset."
- Across three separate studies, this team discovered that this sexual activation helps people initiate relationships by inducing them to project their desires onto prospective partners.
<p>What encourages us to seek out potential partners? What interactions encourage us to keep dating, despite the possibility of being rejected? The sexual behavioral system of humans has evolved over millennia and has been the topic of many scientific studies over the years. The concept of dating and pursuing romantic partners has been a curiosity to everyone, it seems, with <a href="https://www.mentalfloss.com/article/79140/10-fascinating-facts-about-evolution-dating-and-courtship" rel="noopener noreferrer" target="_blank">lists like this one from Mental Floss</a> detailing what dating was like throughout the centuries.</p><p>Ultimately, romantic "success" depends on our ability to target the right potential partner whom we not only find attractive but who is also attracted to us. <a href="https://www.sciencedirect.com/science/article/pii/S0747563218301870" target="_blank">Fear of rejection</a>, self-doubt, and <a href="https://www.verywellmind.com/how-anxiety-can-cause-relationship-problems-1393090" target="_blank">anxiety</a> are just some of the obstacles humans need to overcome to make a meaningful, romantic connection with another person.</p><ul class="ee-ul"></ul>
Being in a frisky mood improves your chances with potential romantic partners
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQzNzk0OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0Mjc3MDA5NH0.lwJquRq9_gTYX5c_2sRzCBfkyWldjMqCJig_kGCL1uA/img.jpg?width=1245&coordinates=0%2C6%2C0%2C98&height=700" id="f2719" class="rm-shortcode" data-rm-shortcode-id="9a29ad6b50ff3868c867fd2d0a64b8aa" data-rm-shortcode-name="rebelmouse-image" alt="man and woman on date woman" />The right mood could land you the right date, according to a new study.
Credit: BlueSkyImage on Shutterstock
<p><a href="https://www.eurekalert.org/pub_releases/2020-09/uor-ffm092320.php" target="_blank" rel="noopener noreferrer">According to a 2020 study</a> by a group of psychologists at the University of Rochester (and the Israeli-based Interdisciplinary Center Herzliya), humans see possible romantic partners as a lot more attractive if they go into the interaction with a "sexy mindset."</p><p><a href="https://www.sas.rochester.edu/psy/people/faculty/reis_harry/" target="_blank" rel="noopener noreferrer">Harry Reis</a>, professor of psychology and the Dean's Professor in Arts, Sciences & Engineering at Rochester, and <a href="https://www.idc.ac.il/en/pages/faculty.aspx?username=birnbag" target="_blank" rel="noopener noreferrer">Gurit Birnbaum</a>, a social psychologist and associate professor of psychology at the IDC (Interdisciplinary Center Herzliya) have dedicated decades of their lives to studying the intricate dynamics of sexual attraction and human sexual behavior. </p><p>In <a href="https://www.rochester.edu/newscenter/relationships-uncertainty-are-you-really-in-to-me-323512/" target="_blank" rel="noopener noreferrer">a previous study,</a> the pair discovered that when people feel greater certainty about a romantic partner's interest, they put more effort into seeing that person again. Additionally, this study found people will rate the possible partner as more "sexually attractive" if they knew the person was interested in seeing them again.</p><p><a href="https://www.eurekalert.org/pub_releases/2020-09/uor-ffm092320.php" target="_blank" rel="noopener noreferrer">For this project</a>, Reis and Birnbaum, along with their team, examined what would happen if a person's sexual system is activated by exposing them to brief sexual cues that induced a thought process that included the potential for sex or heightened attraction. </p><p>Across three separate studies, the team discovered that this sexual activation helps people initiate relationships by inducing them to project their desires onto prospective partners. </p><p><strong>Study one: Immediacy</strong></p><p>In the first study, 112 heterosexual participants (between the ages of 20-32) who were not in a romantic relationship were randomly paired with an unacquainted participant of the opposite sex. Participants introduced themselves to each other (speaking about their hobbies, positive traits, career plans, etc.), all while being recorded. </p><p>The team then coded the recorded interactions and searched for nonverbal expressions of immediacy (such as close proximity, frequent eye contact, smiles, etc.) that could indicate interest in starting a romantic relationship. </p><p>In the study, the team determined that the participants exposed to a sexual stimulus before the meeting (versus those exposed to a neutral stimulus) exhibited more immediacy behaviors towards their potential partners and also perceived the partners as more attractive and/or more interested in them. </p><p><strong>Study two: Interest</strong></p><p>In the second study, 150 heterosexual participants (between the ages of 19-30) who were not in a romantic relationship served as a control for the potential partner's attractiveness and reactions. All participants in study two watched the same pre-recorded video introduction of a potential partner of the opposite sex. They then introduced themselves to the partner while being filmed themselves. </p><p>The researchers found that the activation of the sexual system led to participants viewing the potential partner as more attractive as well as more interested in them. </p><p><strong>Study three: How it all ties together</strong></p><p>In the third and final study, the team investigated whether a partner's romantic interest could explain why sexual activation impacts how we view other people's romantic interest in ourselves. </p><p>In this study, 120 single heterosexual participants (between the ages of 21-31) interacted online with another participant who was actually an attractive opposite-sex member of the research team. This was a casual "get-to-know-you" kind of interaction. The participants rated their romantic interest in the other person as well as that person's attractiveness and interest in them.</p><p>Again, the team found that sexual activation increased a person's romantic interest in the other person, which, in turn, predicted that the other person would then be more interested in a romantic partnership as well. </p><p><strong>The takeaway: Positive, romantic thoughts could produce positive, romantic outcomes. </strong></p><p>The basis of this multi-study theory is simple: Having active sexual thoughts arouses romantic interest in a prospective partner and often leads to an optimistic outlook on dating. </p><p>"Sexual feelings do more than just motivate us to seek out partners. It also leads us to project our feelings onto the other person," <a href="https://www.eurekalert.org/pub_releases/2020-09/uor-ffm092320.php" target="_blank">said Reis to Eurekalert</a>. </p><p>Reis goes on to explain, "...the sexual feelings need not come from the other person; they can be aroused in any number of ways that have nothing to do with the other person."</p>
Keep reading
Show less
Sperm don't slither, they swim in a corkscrew motion
New research reveals that because of an optical illusion, we've been viewing sperm incorrectly for nearly 350 years.
16 August, 2020
Sebastian Kaulitzki/Science Photo Library via Getty Images
- Since 1677, thanks to an optical illusion caused by viewing them in 2D, science has assumed that sperm move toward an egg by lashing their tails from side to side like an eel.
- A new study that used 3D microscopy devices shows that sperm corkscrew forward like an otter.
- This research could be useful for furthering our understanding about the causes of male infertility by giving us a better idea of the mechanisms that underlie sperms' incredible journey to an egg.
<p>Back in 1677, a Dutch scientist named Antonie van Leeuwenhoek, dubbed "<a href="https://www.mentalfloss.com/article/627403/how-sperm-corkscrew-to-eggs" target="_blank" rel="dofollow">the father of microbiology</a>," discovered what appeared to be tiny, squirming "animalcules" in a sample of his own semen observed under his newly developed microscope. He described these microscopic beings, now known as sperm cells, as "a small earth nut with a long tail" that propels itself forward by lashing its tail from side to side similar to an eel swimming in water.</p><p>For the last 350 years, science has accepted that 17th century visual model for sperms' movement toward an egg. </p>
Microscopes were wrong: Sperm corkscrew
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="2bba1faebd6e6d5d81670495a290f57a"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/BQ_3lxlVJ-w?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Now, a team of researchers has finally upended that assumption. A new study published in <a href="https://advances.sciencemag.org/content/6/31/eaba5168" target="_blank" rel="dofollow">Science Advances</a> shows that sperm don't slither like serpents, which is actually an optical illusion. Rather, they corkscrew forward like playful otters.</p><p>Researchers from the United Kingdom and Mexico recently used a high-speed camera and 3D microscopy devices to capture sperm's movement, and what they found will restructure what we understand about one of the most essential biological functions. Rather moving their tail from side to side like a snake, sperms' tails only lash to one side. While this would seemingly cause them to swim in circles, these cells instead rotate their bodies each time their tails lash to the side, thus propelling them in a spiral motion. </p><p>"We were not expecting to find what we found," Hermes Gadêlha, head of the Polymaths Lab at University of Bristol and lead author on the study, <a href="https://www.smithsonianmag.com/science-nature/researchers-discover-how-human-sperm-really-swim-180975453/" target="_blank" rel="noopener noreferrer dofollow">told Smithsonian Magazine</a>. "The aim of the project was 'blue sky' [or broad] research, to understand how sperm moves in three dimensions. And the result has completely changed the belief system that we have."</p><p>So, how did it take us until 2020 to modify van Leeuwenhoek's 17th century assumption? The primary reason that his sperm-model went undisputed for centuries was because researchers have continued to use 2D technology to view sperm. If you were to look at sperm under a modern microscope, you would probably make the same incorrect assumption about their movement that van Leeuwenhoek made. The depth that 3D imaging provided allowed researchers to see that the sperm's body is spinning in a rotated motion, whereas in flat picture it looks like it's simply moving its tail to each side. </p><p>Another problem that has existed for researchers, <a href="https://theconversation.com/sperm-fooled-scientists-for-350-years-they-spin-not-swim-140669" target="_blank" rel="noopener noreferrer dofollow">according to Gadêlha</a>, is that sperm's size and speed make them extremely difficult to observe closely. In fact, they can complete approximately 20 propulsions in less than a second. </p>Broader implications about reproduction
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU2MDk4MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MTYwMjY4OH0.3evBQkLlB53d4PpRdhEamnVMOayH1OtIQa17aBjXgJ0/img.jpg?width=1245&coordinates=0%2C26%2C0%2C26&height=700" id="11d55" class="rm-shortcode" data-rm-shortcode-id="7b3b7ddc6b121920db2c5a0938e0e1ad" data-rm-shortcode-name="rebelmouse-image" alt="rendering of sperm surrounding egg" />Human eggs "choose" sperm by using a chemical signal to attract certain sperm.
Getty Images
<p>As this study highlights, what science reveals to us about the world is constantly in flux as our technology, cultural beliefs, and the questions we ask evolve. This discovery about sperms' true movement builds upon a slew of recent studies that are radically challenging what we know about human reproduction. For example, it was long believed that the human egg had no active role when it came to its interaction with sperm. Earlier this summer, <a href="https://phys.org/news/2020-06-human-eggs-men-sperm.html#:~:text=Human%20eggs%20use%20chemical%20signals%20to%20attract%20sperm.&text=Humans%20spend%20a%20lot%20of,eggs%20can%20%22choose%22%20sperm." target="_blank">a study found</a> that human eggs "choose" sperm by using a chemical signal to attract certain sperm. Last year, <a href="https://theconversation.com/how-mens-damaged-sperm-could-play-significant-role-in-recurrent-miscarriage-109683" target="_blank">another study</a> found that men's sperm, when damaged, can play a larger role in recurrent miscarriages than previously thought.</p><p>While these cultural dynamics are interesting, this new study on sperms' swimming techniques holds some practical implications as well. It could be useful for future research about the causes of male infertility. For example, we now have a better idea of mechanisms that underlie sperms' incredible journey to an egg and that could help scientists understand why some sperm have a more difficult time making it there to successfully procreate.</p>
Keep reading
Show less
What really happens in your body and brain when you orgasm?
You may be surprised at how your body and brain react to this type of pleasure.
04 August, 2020
Image by gpointstudio on Shutterstock
- An orgasm is described as a feeling of intense pleasure that happens during sexual activity.
- By studying the brain activity of people experiencing orgasms, researchers have been able to pinpoint some of the key changes that occur.
- These changes include heightened sensitivity to areas of the brain that control how we feel pain, making us less sensitive to it.
<p>An orgasm is described as a feeling of intense pleasure that happens during sexual activity. While some people experience orgasms differently than others, there are some key changes that occur in the mind and body.</p><p><span></span>By studying the brain activity of people experiencing orgasms, researchers have been able to pinpoint some of these key changes that occur. Using fMRI machines (functional magnetic resonance imaging) or PET scans (positron emission tomography), they were able to measure blood flow and neuron activity inside the brain during climax.</p>
What really happens in the brain during orgasm?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUzMjAzOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNzk0MTg3N30.XMncIeu8myjL-bgF936p4NYAmXpCbI7dQl1AXuXBZc0/img.jpg?width=1245&coordinates=0%2C93%2C0%2C94&height=700" id="aab53" class="rm-shortcode" data-rm-shortcode-id="309e980e413d58c454f6fed13596917f" data-rm-shortcode-name="rebelmouse-image" alt="3D rendering of hypothalamus lighting up" />The hypothalamus, which plays a key role in releasing hormones like dopamine and oxytocin, is one of the regions of the brain that lights up during orgasm.
Image by SciePro on Shutterstock
<p><strong>Does the "logical" part of your brain shut down? That's hotly debated.</strong></p><p><strong></strong>There may be a reason why you feel bold and uninhibited during your climax.<br></p><p>"The lateral orbitofrontal cortex becomes less active during sex. This is the part of the brain that is responsible for reason, decision making, and value judgments. The deactivation of this part of the brain is also associated with decreases in fear and anxiety," explains clinical psychologist <a href="https://www.betweenusclinic.com/about-us/" target="_blank">Daniel Sher</a>. </p><p>However, not all experts in the field agree with this widely publicized study's findings. Recent (2017) research suggests otherwise, with results that show that these areas of the brain <a href="https://pubmed.ncbi.nlm.nih.gov/28986148/" target="_blank">did not deactivate within the 10 female participants of this study</a>.</p><p><strong>Parts of your brain associated with memories, touch, and movement may light up. </strong></p><p>Research has found that the hypothalamus, thalamus, and substantia nigra may light up during orgasm. "Dirty Minds: How Our Brains Influence Love, Sex and Relationships" author <a href="http://kaytsukel.com/" target="_blank">Kayt Sukel</a> <a href="https://www.theguardian.com/science/blog/2011/nov/16/orgasm-mri-scanner" target="_blank">was interviewed</a> for her work alongside researchers who studied the effect of an orgasm on the brain while she was in an MRI machine.</p><p>The thalamus helps integrate information about touch, movement, and sexual memories/fantasies. This could explain how you call upon sexual memories and fantasies (or why your imagination is able to be more active) during sexual arousal and peak. </p><p><strong>Oxytocin builds up and is released.</strong></p><p>Oxytocin is defined as a "bonding" hormone. The forming of oxytocin during sex happens in the pituitary glands and it is then released in the hypothalamus. The <a href="https://www.healthline.com/human-body-maps/hypothalamus" target="_blank">hypothalamus</a> plays a key role in many important functions including the releasing of other hormones (like dopamine), regulation of body temperature, controlling of appetite, and of course, the management of sexual behaviors.</p><p><strong>A surge of dopamine is released. </strong></p><p>During orgasm, your brain works hard to produce various hormones, like the aforementioned oxytocin. In that cocktail of hormones is dopamine, which is released at the moment of orgasm. Dopamine is responsible for feelings of pleasure and desire and therefore acts as a motivation to keep experiencing those feelings of pleasure and desire. </p><p>Dopamine is formed <a href="https://thebrain.mcgill.ca/flash/d/d_03/d_03_cr/d_03_cr_que/d_03_cr_que.html" target="_blank">in the part of the brain</a> that receives information from several other areas in order to define if your needs (specifically your human needs) are being satisfied. </p><p><strong>The release of endorphins, oxytocin, and vasopressin make you less sensitive to pain during sex. </strong></p><p>For many, pain and sex go hand in hand. Many people enjoy a little bit of pain during sex, and there is actually a very good reason for this: you're less susceptible to pain during sex. The pituitary gland is activated during sex, which then frees your brain up to release all kinds of endorphins that are able to promote pain reduction. </p><p>An interesting thing to note is that some of the same areas of the brain that are active during sex are also active when you experience pain. <a href="https://pubmed.ncbi.nlm.nih.gov/4000685/" target="_blank">A very interesting 1985 study</a> looked at the correlation between vaginal stimulation and the elevation of pain. </p><p><strong>In people who are unable to feel genital stimulation, the brain may actually be able to "remap" itself. </strong></p><p>People who have suffered lower-body paralysis can still achieve orgasm through stimulation of other body parts such as the nipples. In this case, the brain actually creates new pathways to pleasure that doesn't involve our genitalia. <a href="https://www.seattletimes.com/seattle-news/health/paralyzed-women-rediscover-orgasms/" target="_blank">This Seattle Times article</a> details paralyzed women who were able to rediscover their ability to orgasm through various other sensations.<br></p><p><strong>Having orgasms can keep your brain healthy. </strong></p><p>Because there is a significant increase in blood flow across multiple areas of the brain so dramatically when we achieve orgasm, it's entirely likely that orgasms may have developed in part to keep our brains healthy.</p>What really happens in the body when you orgasm?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUzMjAzOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwOTYyMzA2Nn0.-etGxz-ejxnP2n4CJ4OVoQy5KrrLL2uTxet7i-nBFZk/img.jpg?width=1245&coordinates=0%2C52%2C0%2C52&height=700" id="4b6fe" class="rm-shortcode" data-rm-shortcode-id="648070a56f9fea934d8780dba38bfb1f" data-rm-shortcode-name="rebelmouse-image" alt="woman holding blanket in her hand" />What really happens in the body when we orgasm?
Photo by NATNN on Shutterstock
<p><strong>Your body swells and becomes more sensitive.</strong></p><p>While men experience the obvious swelling in the genitals due to increased blood flow, women can experience some forms of swelling during sex as well. From your breasts to your vulva, many women experience swelling during sexual arousal and release. </p><p><strong>Your heart rate quickens, which leads to euphoria. </strong></p><p>Of course, your heart rate elevates when you're experiencing orgasm, but along with that, you also experience a blood pressure rise and your breathing rate also increases. Both of these things are considered mild aerobic activity responses and could factor into the kind of euphoria you feel during sexual experiences - similar to a "runners high."</p><p><strong>Muscles in the vagina, anus, and uterus contract and release - like a workout.</strong></p><p>Not only is your pulse racing, but you may also be working out some of the muscles in your body (aside from the ones you're using to physically have sex). </p><p>According to <a href="https://www.bustle.com/p/9-things-that-happen-to-your-body-when-you-have-orgasm-that-you-never-realized-8487239" target="_blank">Bustle</a>, "Increased blood flow to the genitals during orgasm also maintains the integrity of the smooth muscle that lines the vagina, rectum and connective tissue between the penile shaft and scrotum."</p><p><strong>Orgasms may improve allergy symptoms or clear blocked nasal passages.</strong></p><p>"Orgasms can be effective at opening blocked nasal passages and can alleviate some allergy and congestion symptoms," according to sexologist and clinical professional counselor Dr. Laura Deitsch.</p>
Keep reading
Show less
The formula that predicts every animal’s life story
Life forms on Earth are wildly varied, but scientists discover a single formula that predicts every one's life cycle.
13 December, 2019
- Earth's species diversity is stunning, but there are a couple of battles we all face.
- Our response to these challenges set the course of our lives.
- Plug in a couple of variables, and a new formula predicts how we live, reproduce, and die.
<p>The diversity of life on Earth is mind-boggling. What could humans, octopuses, birds, and plankton possibly have in common? Well, the truth is that all of us/them have evolved to overcome some of the same biophysical constraints. As a result, says a study published in <a href="https://www.pnas.org/content/early/2019/12/09/1907702116.short?rss=1&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Pnas-RssFeedOfEarlyEditionArticles+%28Early+Edition%29" target="_blank"><em>Proceedings of the National Academy of Sciences</em></a>, certain universal rules <em>can</em> be derived that encompass <em>all</em> of our life histories. </p><p>"If you impose these constraints on the mathematical model, then certain unifying patterns fall out," says ecology and evolutionary biology postdoctoral fellow <a href="https://www.researchgate.net/profile/Joseph_Burger" target="_blank">Joseph "Robbie" Burger</a>, of the Institute of the Environment and the Bridging Biodiversity and Conservation Science program at the University of Arizona.</p>
Our common struggles
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjE2NDI0OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNzU5MTYyNn0.CItlv_weyCrvuIgIyt1PCvDTPlcN668DqcRZjWwLQos/img.jpg?width=1245&coordinates=0%2C49%2C340%2C291&height=700" id="d3ae8" class="rm-shortcode" data-rm-shortcode-id="0174b4109c5c9743ebf2eca44189e0e0" data-rm-shortcode-name="rebelmouse-image" />Image source: Budimir Jevtic/Shutterstock
<p style="margin-left: 20px;"><em>"The life histories of animals reflect the allocation of metabolic energy to traits that determine fitness and the pace of living. Here, we extend metabolic theories to address how demography and mass–energy balance constrain allocation of biomass to survival, growth, and reproduction over a life cycle of one generation." — Burger, et al</em></p><p>These challenges present themselves in different ways in different habitats, and so our responses vary. Nonetheless, we all aspire to survive for a while, reproduce, and get out of the way of our offspring. Whether one is a turtle laying millions of eggs on a beach or an elephant giving birth to one calf at a time, our goals are essentially the same.</p><p>The study begins with an axiom: "Energy is the staff of life." The sustainable allocation of energy is therefore something all species need to establish in order to survive. According to the study, there are two areas in which workable tradeoffs have to be found for any creatures:</p> <ol> <li>A "mass–energy balance. . . so that over a lifespan in each generation, all of the energy acquired. . . is expended on respiration and production, and energy allocated to production exactly matches energy lost to mortality."</li> <li>A "constraint on mortality so that, regardless of the number of offspring produced, only two survive to complete a life cycle of one generation."</li> </ol>Predicting a species’ life cycle
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjE2NDI1NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0MDQ3MDA5NH0.PlUP9AwfCh22BqkACVKYu5LSzotuzyIbJbZ4SxUCz4o/img.jpg?width=980" id="f976e" class="rm-shortcode" data-rm-shortcode-id="3f741d2773d967454e7c875497f17101" data-rm-shortcode-name="rebelmouse-image" />Image source: Ihnatovich Maryia/Shutterstock
<p>Burger and his colleagues derived a predictive formula informed by a species' response to the two constraints.</p><p>"What's so cool about these equations," says Burger, "is that to solve it, all you have to know are two values — the size of the offspring at independence and the adult size. If you plug that into the equation, you get the number of offspring an organism will produce in a lifetime [as well as] myriad other life history characteristics."</p><p>Assembling and analyzing a database of 36 animals' life histories, Burger and his colleagues were able to create a formula that can accurately predict a number of things about any species' life story:</p> <ul> <li>the length of a species' single generation</li> <li>the species' mortality rate</li> <li>the number of offspring the species reproduces and the size of the offspring</li> <li>the type and extent of parental care common to the species</li> </ul> <p>Prior to the new study, the only widely used formula had been the notion that the smaller the offspring the more of them there were, and vice versa. Burger's finding indicate that things are not quite that simple.</p><p>The new formula is of more than academic importance. As we work to understand habitat changes caused by humankind and the species they impact, and as we seek to help those species survive, knowledge of their natural life cycles is invaluable, particularly given the incredible variety of life forms involved, many of whose life stories remain largely hidden from us.</p><p>"We now need to put these equations to practice," asserts Burger, "by developing user-friendly programming tools, collaborating with field scientists refine ecosystem models and informing management decisions."</p>
Keep reading
Show less
Image source: Volodymyr Tverdokhlib/Shutterstock
- A study from Rutgers documents age-related reproductive factors for men.
- Beyond a certain age, men risk a variety of serious hazards to their mates and offspring.
- Men planning to father children should consider banking their sperm before reaching 35.
<p>We've often heard of a woman's "biological clock" ticking as the age window approaches during which conception, a safe delivery, and a healthy child are most likely to occur. It turns out men have a biological clock of their own. A <a href="https://www.maturitas.org/article/S0378-5122(19)30134-3/fulltext" target="_blank">study</a> from <a href="https://news.rutgers.edu/research-news/older-fathers-put-health-partners-unborn-children-risk-rutgers-study-finds/20190510#.XNwyfS2ZMUH" target="_blank">Rutgers Robert Wood Johnson Medical School</a> now identifies men's ideal reproduction window. As with women, there's reason for men to be concerned about successfully reproducing beyond a certain age, even though there's been a 10% increase over the past 40 years of infants born to men over 45, which is beyond the recommended age. Author <a href="https://rwjms.rutgers.edu/departments_institutes/whi_new/faculty/index.html" target="_blank">Gloria Bachmann</a> says, "While it is widely accepted that physiological changes that occur in women after 35 can affect conception, pregnancy and the health of the child, most men do not realize their advanced age can have a similar impact." Bachmann adds that "In addition to decreasing fertilization potential, this can also influence the pregnancy itself, as is noted by increased pregnancy risks when conception is successful." This is even the case when the woman is younger than 25.</p>
Risking the health of loved ones
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTQ2NzcwNi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzgyNDM3MH0.WlJDUc1wryzth9MkKAs7PStRIPOvIpXZ39HMcJKv7No/img.jpg?width=980" id="7971a" class="rm-shortcode" data-rm-shortcode-id="4f48ea95f663221539391d7e1dcdbabe" data-rm-shortcode-name="rebelmouse-image" />Image source: Janko Ferlič/Unsplash
<p>According to the study, men 45 and older risk a range of hazards:</p> <ul> <li>The put their partners at increased risk of experiencing pregnancy complications: These include gestational diabetes, preeclampsia, and pre-term delivery.</li> <li>Infants of such fathers are more frequently born with issues: They're more apt to be premature or succumb to late stillbirth. Low birth weight, a greater prevalence of newborn seizures and birth defects are also more likely to occur. The report cites cleft palate and congenital heart disease as among these defects.</li> <li>Maturing children continue to have problems: These include a higher incidence of childhood cancer, cognitive and psychiatric disorders, and autism. "Although it is well documented that children of older fathers are more likely to be diagnosed with schizophrenia — one in 141 infants with fathers under 25 versus one in 47 with fathers over 50 — the reason is not well understood," says Bachmann. The risk of autism decreases with fathers under 25, increases at 30, stabilizes at 40, and again rises at 50.</li></ul>Fatherhood outside the window
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTQ2NzcxMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMzQ1ODgyNH0.QKXDRSjOCH8_zit8K_uT9beKC6OXeAQb8fHl8SqYaFk/img.jpg?width=980" id="907bb" class="rm-shortcode" data-rm-shortcode-id="e6431ebd8db53fc3b0520b5d66716af1" data-rm-shortcode-name="rebelmouse-image" />Image source: olliulli/Shutterstock
<p>The main issue seems to be a degradation with age of the quality of sperm. In the same way that fitness fades with age for the individual, sperm also declines. While there's not yet a consensus on the point at which "advanced paternal age" sets in, and more research is needed, the range is somewhere between 35 and 45 years of age.</p><p>Whenever it is, older men have a reduced sperm count and the quality of an offspring's inherited DNA may be sub-optimal.</p><p>Bachmann recommends that men planning to produce offspring later in life bank their sperm before hitting 35 for subsequent insemination when the time is right.</p><p>The study refers, of course, to reproduction and has nothing to say about being an older father of a partner's child with a previous mate or an adopted child.</p>
Keep reading
Show less
Popular
