Big ideas.
Once a week.
Subscribe to our weekly newsletter.
Evolution: That famous ‘march of progress’ image is just wrong
Some fish evolved legs and walked onto the land. Right?

Evolution explains how all living beings, including us, came to be. It would be easy to assume evolution works by continuously adding features to organisms, constantly increasing their complexity.
Some fish evolved legs and walked onto the land. Some dinosaurs evolved wings and began to fly. Others evolved wombs and began to give birth to live young.
Yet this is one of the most predominant and frustrating misconceptions about evolution. Many successful branches of the tree of life have stayed simple, such as bacteria, or have reduced their complexity, such as parasites. And they are doing very well.
In a recent study published in Nature Ecology and Evolution, we compared the complete genomes of over 100 organisms (mostly animals), to study how the animal kingdom has evolved at the genetic level. Our results show that the origins of major groups of animals, such as the one comprising humans, are linked not to the addition of new genes but to massive gene losses.
The evolutionary biologist Stephen Jay Gould was one of the strongest opponents of "the march of progress", the idea that evolution always results in increased complexity. In his book Full House (1996), Gould uses the model of the drunkard walk. A drunkard leaves a bar in a train station and clumsily walks back and forth over the platform, swinging between the bar and the train tracks. Given enough time, the drunkard will fall in the tracks and will get stuck there.
The platform represents a scale of complexity, the pub being the lowest complexity and the tracks the maximum. Life emerged by coming out of the pub, with the minimum complexity possible. Sometimes it randomly stumbles towards the tracks (evolving in a way that increases complexity) and other times towards the pub (reducing complexity).
No option is better than the other. Staying simple or reducing complexity may be better for survival than evolving with increased complexity, depending on the environment.
But in some cases, groups of animals evolve complex features that are intrinsic to the way their bodies work, and can no longer lose those genes to become simpler - they become stuck in the train tracks. (There are no trains to worry about in this metaphor.) For example, multicellular organisms rarely go back to become unicellular.
If we only focus on the organisms trapped in the train tracks, then we have a biased perception of life evolving in a straight line from simple to complex, mistakenly believing that older lifeforms are always simple and newer ones are complex. But the real path to complexity is more tortuous.
Together with Peter Holland from the University of Oxford, we looked into how genetic complexity has evolved in animals. Previously, we have shown that the addition of new genes was key to the early evolution of the animal kingdom. The question then became whether that was the case during the later evolution of animals.
Studying the tree of life
Most animals can be grouped into major evolutionary lineages, branches on the tree of life showing how the animals alive today evolved from a series of shared ancestors. In order to answer our question, we studied every animal lineage for which a genome sequence was publicly available, and many non-animal lineages to compare them against.
One animal lineage is that of the deuterostomes, which includes humans and other vertebrates, as well as sea stars or sea urchins. Another is the ecdysozoans, comprising the arthropods (insects, lobsters, spiders, millipedes), and other moulting animals such as roundworms. Vertebrates and insects are considered some of the most complex animals. Finally, we have one lineage, the lophotrochozoans, that includes animals such as molluscs (snails, for example) or annelids (earthworms), among many others.
We took this diverse selection of organisms and looked to see how they were related on the tree of life and what genes they shared and didn't share. If a gene was present in an older branch of the tree and not in a younger one, we inferred that this gene had been lost. If a gene wasn't present in older branches but appeared in a younger branch, then we considered it a novel gene that had been gained in the younger branch.
A tree of life diagram showing the changing number of genes of different animal groups. Downward pointing orange triangles indicate gene losses. Upwards pointing green triangles indicate gene gains. The bigger the triangle, the greater the change. (Jordi Paps, Author provided)
The results showed unprecedented numbers of genes lost and gained, something never seen before in previous analyses. Two of the major lineages, the deuterostomes (including humans) and the ecdysozoans (including insects), showed the largest number of gene losses. In contrast, the lophotrochozoans show a balance between gene novelties and losses.
Our results confirm the picture given by Stephen Jay Gould by showing that, at the gene level, animal life emerged by leaving the pub and making a large leap in complexity. But after the initial enthusiasm, some lineages stumbled closer to the pub by losing genes, while other lineages drifted towards the track by gaining genes. We consider this the perfect summary of evolution, a booze-induced random choice between the bar and the train track. Or, as the internet meme says, "go home evolution, you are drunk".
Jordi Paps, Lecturer, School of Biological Sciences, University of Bristol, University of Bristol and Cristina Guijarro-Clarke, PhD Candidate in Evolution, University of Essex.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
- The theory of evolution: another reason to be an existentialist? - Big ... ›
- It's time we stopped human evolution – geneticist ›
‘Designer baby’ book trilogy explores the moral dilemmas humans may soon create
How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.
- A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
- It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
- While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Tribalism and discrimination
<p>One question the "Genetic Pressure" series explores: What would tribalism and discrimination look like in a world with designer babies? As designer babies grow up, they could be noticeably different from other people, potentially being smarter, more attractive and healthier. This could breed resentment between the groups—as it does in the series.</p><p>"[Designer babies] slowly find that 'everyone else,' and even their own parents, becomes less and less tolerable," author Eugene Clark told Big Think. "Meanwhile, everyone else slowly feels threatened by the designer babies."</p><p>For example, one character in the series who was born a designer baby faces discrimination and harassment from "normal people"—they call her "soulless" and say she was "made in a factory," a "consumer product." </p><p>Would such divisions emerge in the real world? The answer may depend on who's able to afford designer baby services. If it's only the ultra-wealthy, then it's easy to imagine how being a designer baby could be seen by society as a kind of hyper-privilege, which designer babies would have to reckon with. </p><p>Even if people from all socioeconomic backgrounds can someday afford designer babies, people born designer babies may struggle with tough existential questions: Can they ever take full credit for things they achieve, or were they born with an unfair advantage? To what extent should they spend their lives helping the less fortunate? </p>Sexuality dilemmas
<p>Sexuality presents another set of thorny questions. If a designer baby industry someday allows people to optimize humans for attractiveness, designer babies could grow up to find themselves surrounded by ultra-attractive people. That may not sound like a big problem.</p><p>But consider that, if designer babies someday become the standard way to have children, there'd necessarily be a years-long gap in which only some people are having designer babies. Meanwhile, the rest of society would be having children the old-fashioned way. So, in terms of attractiveness, society could see increasingly apparent disparities in physical appearances between the two groups. "Normal people" could begin to seem increasingly ugly.</p><p>But ultra-attractive people who were born designer babies could face problems, too. One could be the loss of body image. </p><p>When designer babies grow up in the "Genetic Pressure" series, men look like all the other men, and women look like all the other women. This homogeneity of physical appearance occurs because parents of designer babies start following trends, all choosing similar traits for their children: tall, athletic build, olive skin, etc. </p><p>Sure, facial traits remain relatively unique, but everyone's more or less equally attractive. And this causes strange changes to sexual preferences.</p><p>"In a society of sexual equals, they start looking for other differentiators," he said, noting that violet-colored eyes become a rare trait that genetically engineered humans find especially attractive in the series.</p><p>But what about sexual relationships between genetically engineered humans and "normal" people? In the "Genetic Pressure" series, many "normal" people want to have kids with (or at least have sex with) genetically engineered humans. But a minority of engineered humans oppose breeding with "normal" people, and this leads to an ideology that considers engineered humans to be racially supreme. </p>Regulating designer babies
<p>On a policy level, there are many open questions about how governments might legislate a world with designer babies. But it's not totally new territory, considering the West's dark history of eugenics experiments.</p><p>In the 20th century, the U.S. conducted multiple eugenics programs, including immigration restrictions based on genetic inferiority and forced sterilizations. In 1927, for example, the Supreme Court ruled that forcibly sterilizing the mentally handicapped didn't violate the Constitution. Supreme Court Justice Oliver Wendall Holmes wrote, "… three generations of imbeciles are enough." </p><p>After the Holocaust, eugenics programs became increasingly taboo and regulated in the U.S. (though some states continued forced sterilizations <a href="https://www.uvm.edu/~lkaelber/eugenics/" target="_blank">into the 1970s</a>). In recent years, some policymakers and scientists have expressed concerns about how gene-editing technologies could reanimate the eugenics nightmares of the 20th century. </p><p>Currently, the U.S. doesn't explicitly ban human germline genetic editing on the federal level, but a combination of laws effectively render it <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">illegal to implant a genetically modified embryo</a>. Part of the reason is that scientists still aren't sure of the unintended consequences of new gene-editing technologies. </p><p>But there are also concerns that these technologies could usher in a new era of eugenics. After all, the function of a designer baby industry, like the one in the "Genetic Pressure" series, wouldn't necessarily be limited to eliminating genetic diseases; it could also work to increase the occurrence of "desirable" traits. </p><p>If the industry did that, it'd effectively signal that the <em>opposites of those traits are undesirable. </em>As the International Bioethics Committee <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">wrote</a>, this would "jeopardize the inherent and therefore equal dignity of all human beings and renew eugenics, disguised as the fulfillment of the wish for a better, improved life."</p><p><em>"Genetic Pressure Volume I: Baby Steps"</em><em> by Eugene Clark is <a href="http://bigth.ink/38VhJn3" target="_blank">available now.</a></em></p>Octopus-like creatures inhabit Jupiter’s moon, claims space scientist
A leading British space scientist thinks there is life under the ice sheets of Europa.
Jupiter's moon Europa has a huge ocean beneath its sheets of ice.
- A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
- Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
- The moon is one of Jupiter's 79.
Neil deGrasse Tyson wants to go ice fishing on Europa
<div class="rm-shortcode" data-media_id="GLGsRX7e" data-player_id="FvQKszTI" data-rm-shortcode-id="f4790eb8f0515e036b24c4195299df28"> <div id="botr_GLGsRX7e_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/GLGsRX7e-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"></script> </div>Water Vapor Above Europa’s Surface Deteced for First Time
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="9c4abc8473e1b89170cc8941beeb1f2d"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/WQ-E1lnSOzc?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>Lair of giant predator worms from 20 million years ago found
Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.
Bobbit worm (Eunice aphroditois).
- Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
- The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
- The creatures can reach several meters in length and famously ambush their pray.
A three-dimensional model of the feeding behavior of Bobbit worms and the proposed formation of Pennichnus formosae.
Credit: Scientific Reports
Beware the Bobbit Worm!
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="1f9918e77851242c91382369581d3aac"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/_As1pHhyDHY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>FOSTA-SESTA: Have controversial sex trafficking acts done more harm than good?
The idea behind the law was simple: make it more difficult for online sex traffickers to find victims.
Has FOSTA-SESTA really lived up to it's promise of protecting sex trafficking victims - or has it made them easier to target?
- SESTA (Stop Enabling Sex Traffickers Act) and FOSTA (Allow States and Victims to Fight Online Sex Trafficking Act) started as two separate bills that were both created with a singular goal: curb online sex trafficking. They were signed into law by former President Trump in 2018.
- The implementation of this law in America has left an international impact, as websites attempt to protect themselves from liability by closing down the sections of their sites that sex workers use to arrange safe meetings with clientele.
- While supporters of this bill have framed FOSTA-SESTA as a vital tool that could prevent sex trafficking and allow sex trafficking survivors to sue those websites for facilitating their victimization, many other people are strictly against the bill and hope it will be reversed.
What is FOSTA-SESTA?
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="723125b44601d565a7c671c7523b6452"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/WBaqDjPCH8k?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>SESTA (Stop Enabling Sex Traffickers Act) and FOSTA (Allow States and Victims to Fight Online Sex Trafficking Act) were signed into law by former President Trump in 2018. There was some argument that this law may be unconstitutional as it could potentially violate the <a href="https://constitution.congress.gov/constitution/amendment-1/" target="_blank">first amendment</a>. A criminal defense lawyer explains this law in-depth in <a href="https://www.youtube.com/watch?v=RoWx2hYg5uo&t=38s" target="_blank" rel="nofollow">this video</a>. </p><p><strong>What did FOSTA-SESTA aim to accomplish?</strong></p><p>The idea behind the law was simple: make it more difficult for online sex traffickers to find victims. FOSTA-SESTA started as two separate bills that were both created with a singular goal: curb online sex trafficking. Targeting websites like Backpage and Craigslist, where sex workers would often arrange meetings with their clientele, FOSTA-SESTA aimed to stop the illegal sex-trafficking activity being conducted online. While the aim of FOSTA-SESTA was to keep people safer, these laws have garnered international speculation and have become quite controversial. </p><p><a href="https://www.businesswire.com/news/home/20180321006214/en/National-Anti-Trafficking-Coalition-Celebrates-Survivors-Senate-Passes" target="_blank" rel="noopener noreferrer">According to BusinessWire</a>, many people are in support of this bill, including the National Center for Missing and Exploited Children and World Without Exploitation (WorldWE). </p><p>"With the growth of the Internet, human trafficking that once happened mainly on street corners has largely shifted online. According to the National Center for Missing & Exploited Children, 73 percent of the 10,000 child sex trafficking reports it receives from the public each year involve ads on the website Backpage.com."</p><p>As soon as this bill was <a href="https://www.pivotlegal.org/sesta_fosta_censoring_sex_workers_from_websites_sets_a_dangerous_precedent" target="_blank" rel="noopener noreferrer">signed into law</a>, websites where sex workers often vetted and arranged meetings with their clients could now be held liable for the actions of the millions of people that used their sites. This meant websites could be prosecuted if they engaged in "the promotion or facilitation of prostitution" or "facilitate traffickers in advertising the sale of unlawful sex acts with sex trafficking victims." </p><p><strong>The bill's effects were felt around the world — from Canadians being unhappy with the impact of this American bill to U.K. politicians considering the implementation of similar laws in the future.</strong> </p><p>Heather Jarvis, the program coordinator of the Safe Harbour Outreach Project (SHOP), which supports sex workers in the St. John's area, <a href="https://www.cbc.ca/news/canada/newfoundland-labrador/heather-jarvis-website-shutdown-1.4667018" target="_blank" rel="noopener noreferrer">explained to CBC in an interview</a> that the American bill is impacting everyone, everywhere: "When laws impact the internet — the internet is often borderless — it often expands across different countries. So although these are laws in the United States, what we've seen is they've been shutting down websites in Canada and other countries as well."</p><p>Jarvis suggests in her interview that instead of doing what they aimed to do with the bill and improving the safety of victims of sex trafficking or sexual exploitation, the website shutdowns are actually making sex workers less safe. </p><p>While <a href="https://gizmodo.com/the-uk-wants-its-own-version-of-fosta-sesta-that-could-1827420794" target="_blank" rel="noopener noreferrer">one U.K. publication</a> refers to FOSTA-SESTA as "well-intentioned but ultimately deeply-flawed laws," it also mentions that politicians in the United Kingdom are hoping to pursue similar laws in the near future. </p>Has FOSTA-SESTA done more harm than good?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTUxMzY5Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2ODUyNDc4OX0.dSEEzcflJJUTnUCFmuwmPAIA0f754eW7rN8x6L7fcCc/img.jpg?width=1245&coordinates=-68%2C595%2C-68%2C595&height=700" id="69d99" class="rm-shortcode" data-rm-shortcode-id="734759fa254b5a33777536e0b4d7b511" data-rm-shortcode-name="rebelmouse-image" alt="sex worker looking online for a job" data-width="1245" data-height="700" />Is this really going to help, or is this bill simply pushing sex work and sex-related content further into the dark?
Credit: Евгений Вершинин on Adobe Stock
<p>While <a href="https://www.businesswire.com/news/home/20180321006214/en/National-Anti-Trafficking-Coalition-Celebrates-Survivors-Senate-Passes" target="_blank">supporters of this bill</a> have framed FOSTA-SESTA as a vital tool that could prevent sex trafficking and allow sex trafficking survivors to sue those websites for facilitating their victimization, many other people are strictly against the bill and hope it will be reversed.</p><p><strong>One of the biggest problems many people have with this bill is that it forces sex workers into an even more dangerous situation, which is quite the opposite of what the bill had intended to do.</strong> </p><p>According to <a href="https://www.theglobeandmail.com/canada/article-anti-trafficking-activists-cheer-but-sex-workers-bemoan-shutdown-of/" target="_blank" rel="noopener noreferrer">Globe and Mail</a>, there has been an upswing in pimps sending sex workers messages that promise work - which puts sex workers on the losing end of a skewed power-dynamic, when before they could attempt to safely arrange their own meetings online. </p><p><strong>How dangerous was online sex work before FOSTA-SESTA? </strong></p><p><a href="https://www.beyond-the-gaze.com/wp-content/uploads/2018/01/BtGbriefingsummaryoverview.pdf" target="_blank" rel="noopener noreferrer">The University of Leicester Department of Criminology</a> conducted an online survey that focused on the relative safety of internet-based sex work compared with outdoor sex work. According to the results, 91.6 percent of participants had not experienced a burglary in the past 5 years, 84.4 percent had not experienced physical assault in the same period, and only 5 percent had experienced physical assault in the last 12 months. </p><p><a href="https://www.pivotlegal.org/sesta_fosta_censoring_sex_workers_from_websites_sets_a_dangerous_precedent" target="_blank" rel="noopener noreferrer">PivotLegal</a> expresses concerns about this: "It is resoundingly clear, both from personal testimony and data, that attacking online sex work is an assault on the health and safety of people in the real world. In a darkly ironic twist, SESTA/FOSTA, legislation aimed at protecting victims of and preventing human trafficking for the purposes of sexual exploitation, will do the exact opposite."</p><p><strong>Websites are also being hypervigilant (and censoring more content than needed) because they can't possibly police every single user's activity on their platform.</strong> </p><p>Passing this bill meant any website (not just the ones that are commonly used by sex traffickers) could be held liable for their user's posts. Naturally, this saw a general "tightening of the belt" when it came to what was allowed on various platforms. In late 2018, shortly after the FOSTA-SESTA bill was passed, companies like Facebook slowly began to alter their terms and conditions to protect themselves. </p><p>Facebook notably added sections that express prohibited certain sexual content and messages:</p><p style="margin-left: 20px;"><em>"Content that includes an implicit invitation for sexual intercourse, which can be described as naming a sexual act and other suggestive elements including (but not limited to):</em></p><p style="margin-left: 20px;"><em>– vague suggestive statements such as: 'looking forward to an enjoyable evening'</em></p><p style="margin-left: 20px;"><em>– sexual use of language […]</em></p><p style="margin-left: 20px;"><em>– content (self-made, digital or existing) that possibly portrays explicit sexual acts or a suggestively positioned person/suggestively positioned persons."<br><br> </em></p><p>Additionally, sections like this were also added, prohibiting things that could allude to sexual activity: </p><p style="margin-left: 20px;"><em>"Content in which other acts committed by adults are requested or offered, such as:</em></p><p style="margin-left: 20px;"><em>– commercial pornography</em></p><p style="margin-left: 20px;"><em>– partners that share fetishes or sexual interests"</em></p><p>Facebook wasn't the only website to crack down on their policies — the Craigslist classifieds section being removed and Reddit banned quite a large number of sex-worker related subreddits. </p><p><strong>Is FOSTA-SESTA really helpful?</strong> </p><p>This is the question many people are facing with the FOSTA-SESTA acts being passed just a few years ago. Is this really going to help, or is this bill simply pushing sex work and sex-related content further into the dark? Opinions seem to be split down the middle on this — what do you think?</p>What is the ‘self’? The 3 layers of your identity.
Answering the question of who you are is not an easy task. Let's unpack what culture, philosophy, and neuroscience have to say.
