A new edge-essay by Steven Pinker is bound to lead to vehement reactions: The False Allure of Group Selection. It is worth a read – Pinker is a clear writer and so his position is easy to locate, however, I get the feeling that his position is to smooth talk whatever a certain establishment likes to hear being defended. The last time I listened, he told modern society that it is the most peaceful ever (an amazing feat of cherry picking data and re-interpretation). Now it seems he simply roots for the more well established guys in a heated turf battle: who may talk about evolution.
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At Science 2.0, we often joke that biologist Neil Shubin from the University of Chicago can make anything about fish. That's because we've never heard him not able to make anything about fish. His books, talks and research methods show great examples of multidisciplinary research - biology tells us what should have existed, geology tells us the conditions where something might be found and paleontology finds it.
A spine with multiple segments is a feature of land-dwelling animals but the discovery of the same anatomical feature in a 345-million-year-old eel suggests that this complex anatomy arose separately from, and perhaps before, the first species to walk on land.
Researchers announced the discovery of Afrasia djijidae, a new early anthropoid fossil.
The 37-million-year-old Afrasia djijidae resembles another early anthropoid, Afrotarsius libycus, recently discovered at a site of similar age in the Sahara Desert of Libya. That close similarity between Afrasia and Afrotarsius indicates that early anthropoids colonized Africa only shortly before the time when these animals lived. The colonization of Africa by early anthropoids was a pivotal step in primate and human evolution, because it set the stage for the later evolution of more advanced apes and humans there.
There was a time when giant insects ruled the skies and it corresponded to high oxygen levels.
After the evolution of birds, about 150 million years ago, insects got smaller - despite rising oxygen levels. What gives?
Insects reached their biggest sizes about 300 million years ago during the late Carboniferous and early Permian periods. This was the reign of the predatory griffinflies, giant dragonfly-like insects with wingspans of up to 28 inches - creepy. The leading theory attributed their large size to high oxygen concentrations in the atmosphere (over 30 percent, compared to 21 percent today), which allowed giant insects to get enough oxygen through the tiny breathing tubes that insects use instead of lungs.
What evolutionary reason would tiny insects 100 million years ago have for collecting and transporting Gingko pollen? They had highly specialized hairs with a ringed structure to increase their ability to collect pollen grains. Their ringed hairs cannot have grown due to an evolutionary selection benefiting the trees so ancient thysanopterans, so-called thrips (a group of minute insects of less than 2 mm in length) must have fed their larvae with pollen. This suggests that this species formed colonies with larvae living in the ovules of some kind of gingko for shelter and protection, and female insects transporting pollen from the male Gingko cones to the female ovules to feed the larvae and at the same time pollinate the trees.
If you think about it rationally, sex may be fun but it's too much work and, from a reproduction standpoint, the payoff is uncertain. Scientists have speculated for a long time on why all living things don't simply make like amoebas and split.
Scientists believe that sexual reproduction offers two big advantages: It can sweep bad mutations out of the gene pool more quickly. Also, by shuffling parents' genetic material each generation, it increases the likelihood that new genetic combinations will arise that help organisms adapt to their environment.
It wasn't so long ago that antibacterial products, from soaps to hand gels to wipes for your kitchen counter, became ubiquitous in our grocery stores and our daily lives. Not long afterwards, though, we started hearing reports that these products and their even more powerful cousins, antibiotic prescriptions, were actually doing more harm than good--by facilitating the evolution of bacterial resistance to antimicrobials. As it turns out, that may be just be one evolutionary side effect of exposing bacteria to strongly selective anthropogenic pressures.
Polar bears are evolutionarily older and genetically more distinct than believed. This largest Arctic carnivore evolved as early as 600,000 years ago, five times older than previously recognized.
Why do our closest primate cousins spend more time suckling their young than we typically spend nursing ours? This question has been heavily debated over the past several decades, but to date there is more information on the implications of our relatively short lactation periods than on their causes. One reason it has been difficult to address this question empirically is that there is not much variation in large-brained primates in some of the traits that are hypothesized to impact suckling behaviors; thus, it is difficult to explore how these characteristics could affect lactation and parenting.