from the world's big
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.
- 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.
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 Proceedings of the National Academy of Sciences, certain universal rules can be derived that encompass all of our life histories.
"If you impose these constraints on the mathematical model, then certain unifying patterns fall out," says ecology and evolutionary biology postdoctoral fellow Joseph "Robbie" Burger, of the Institute of the Environment and the Bridging Biodiversity and Conservation Science program at the University of Arizona.
Our common struggles
Image source: Budimir Jevtic/Shutterstock
"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
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.
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:
- 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."
- A "constraint on mortality so that, regardless of the number of offspring produced, only two survive to complete a life cycle of one generation."
Predicting a species’ life cycle
Image source: Ihnatovich Maryia/Shutterstock
Burger and his colleagues derived a predictive formula informed by a species' response to the two constraints.
"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."
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:
- the length of a species' single generation
- the species' mortality rate
- the number of offspring the species reproduces and the size of the offspring
- the type and extent of parental care common to the species
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.
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.
"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."
Emotional intelligence is a skill sought by many employers. Here's how to raise yours.
- Daniel Goleman's 1995 book Emotional Intelligence catapulted the term into widespread use in the business world.
- One study found that EQ (emotional intelligence) is the top predictor of performance and accounts for 58% of success across all job types.
- EQ has been found to increase annual pay by around $29,000 and be present in 90% of top performers.
The rough beauty of the American West seems as far as you can get from the polished corridors of power in Washington DC.
The rough beauty of the American West seems as far as you can get from the polished corridors of power in Washington DC. Until you look at the title to the land. The federal government owns large tracts of the western states: from a low of 29.9% in Montana, already more than the national average, up to a whopping 84.5% in Nevada.
Researchers are using technology to make visual the complex concepts of racism, as well as its political and social consequences.
- Often thought of first as gaming tech, virtual reality has been increasingly used in research as a tool for mimicking real-life scenarios and experiences in a safe and controlled environment.
- Focusing on issues of oppression and the ripple affect it has throughout America's political, educational, and social systems, Dr. Courtney D. Cogburn of Columbia University School of Social Work and her team developed a VR experience that gives users the opportunity to "walk a mile" in the shoes of a black man as he faces racism at three stages in his life: as a child, during adolescence, and as an adult.
- Cogburn says that the goal is to show how these "interwoven oppressions" continue to shape the world beyond our individual experiences. "I think the most important and powerful human superpower is critical consciousness," she says. "And that is the ability to think, be aware and think critically about the world and people around you...it's not so much about the interpersonal 'Do I feel bad, do I like you?'—it's more 'Do I see the world as it is? Am I thinking critically about it and engaging it?'"
President Vladimir Putin announces approval of Russia's coronavirus vaccine but scientists warn it may be unsafe.
A new coronavirus vaccine on display at the Nikolai Gamaleya National Center of Epidemiology and Microbiology in Moscow, Russia.
Credit: Alexander Zemlianichenko Jr/ Russian Direct Investment Fund via AP
Medical workers draw blood from volunteers participating in a trial of a coronavirus vaccine at the Budenko Main Military Hospital outside Moscow, Russia.
Credit: Russian Defense Ministry Press Service via AP
A report from the New York Times raises questions over how the teletherapy startup Talkspace handles user data.