Charles Darwin is great, isn’t he? I mean – he discovered the theory of natural selection and by doing so, created an eloquently beautiful framework for studying and understanding the living world around us. He wrote On the Origin of Species (free text here!). He drew this:
“I think case must be that one generation should have as many living as now. To do this and to have as many species in same genus (as is) requires extinction . Thus between A + B the immense gap of relation. C + B the finest gradation. B+D rather greater distinction. Thus genera would be formed. Bearing relation” (next page begins) “to ancient types with several extinct forms”
Every year on February 12 (Darwin’s birthday), evolution enthusiasts celebrate Darwin Day with nerdy games, scientific seminars and frivolity. Mark your calendars! And this year, it may be even better, since bills (yes, plural!) have been introduced to the House of Representatives and to the Senate to officially name February 12, 2015 Darwin Day. Follow the links to read more. And from what I know about scientists, if we were to ever achieve a federal holiday for Darwin, I think we’d party harder than New Years, explode more things than Independence Day and drink more coffee than finals week. Dar-win! Dar-win! Dar-win!
Some days I just need a pick me up. While others take to the internet and fine photos of kittens telling them to hang in there, I seek the adorable face of the pangolin.
Also known as the spiny anteater, it is the only mammal wholly covered in scales. They resemble artichokes on legs. Oh and they are beyond adorable.
However, all 8 species of pangolins are endangered because they have one more distinction: the worlds most trafficked mammal. Their meat has become a delicacy in vietnam, which has rapidly wiped out populations of pangolins across South East Asia.
Read about their plight over at BBC, and for a little Friday pick me up, enjoy these lovely photos of my favorite mammal.
Morphological convergence is one of the most striking patterns in evolution. Just among mammals there are spectacular and bizarre examples of distantly related species that share surprisingly similar adaptations. I bet you’ve heard of saber-toothed cats. But what about marsupial saber-toothed cats? Raccoons are surely familiar, but have you heard of raccoon dogs? Or the earless, eyeless oddity that is the golden mole, which somehow looks almost exactly like the equally earless and eyeless notoryctid marsupial mole? My favorite, though, might be the lesser hedgehog tenrec from Madagascar, which bears the same tiny coat of spiked armor as the common hedgehog but is more closely related to an elephant.
Skull from the marsupial saber-toothed “cat” Thylacosmilus.
Skull from a placental saber-toothed cat Smilodon.
Until recently, most scientists studying evolutionary convergence have focused on the converged phenotype (external appearance), but with the arrival of ever-cheaper DNA sequencing technologies, scientists can efficiently study patterns of convergent genotypes across thousands of genes in species that appear to have converged at the phenotypic level.
Now, I know dancing sharks are the preferred marine species of the moment, but allow me to reignite your interest in some other denizens of the sea. Last month, a team of researchers published a study in Nature examining how genes in three marine mammal lineages might have converged independently on the same solution to the very hard physiological problem of living in the ocean after millions of years evolving on land (Foote et al. 2015). Their results are hardly conclusive but do illustrate a compelling new way to think about and study convergence now that genomes are getting so cheap to produce.
Katy Perry and her dancing sharks at the 2015 Super Bowl
In academia we often talk about the “two body problem”. By that I mean the difficulty of finding two academic jobs in one place, often causing one partner to make sacrifices in their career.
That sucks and I’m sorry.
But I think it’s important, especially when we’re talking about opportunities for women and minorities, to recognize that academia is hard for everyone. And being single and moving to a new place (which academia almost constantly requires), you lack the support system that a partner provides. Additionally, living in remote college towns and seeking a partner is difficult to impossible. This is especially true for women and the LGBT community and exacerbated as we get older.
This “one body problem” is summed up and explained nicely in this post over on EcoEvo.
Although known to occur in its (much smaller) cousins the dwarf sperm whale (Kogia sima) and the pygmy sperm whale (Kogia breviceps), photographers recently experienced defensive defecation by the sperm whale (Physeter macrocephalus) for the first time ever! Sperm whales can reach up to 67 feet (20.5 meters) long – with almost a thousand feet (>300 meters) of intestine and four stomachs. I was unable to convert those numbers to fecal volume, but I imagine it’s a lot.
The whale approached Wilk and his three colleagues, pointed downwards, and began to evacuate its bowels. To make matters worse, it then started to churn up the water. “Like a bus-sized blender, it very quickly and effectively dispersed its faecal matter into a cloud,” says Wilk.
Now, doesn’t the make you want to pursue nature photography as a career? (It’s totally ok if the answer is yes.) Click here for a few more details and a little gif!
The New York Times reports that monarch butterflies migrating from North America to central Mexico appear to be doing better than last year, when the over-wintering colony occupied just 1.7 acres. This year’s survey finds the butterflies have filled 2.8 acres, which seems like a solid improvement until you consider that the peak colony size, since record-keeping started, was 44.5 acres.
(Incidentally, 44.5 acres is more than 40 American football fields of forest covered with roosting monarch butterflies.)
The monarchs that migrate to Mexico aren’t the only population — there’s another migratory route on the U.S. Pacific coast, and there are non-migratory populations in Florida, Hawaii, and even New Zealand. But the Mexico overwintering site represents what used to be the single largest monarch population, butterflies that spend summer across most of North America east of the Rocky Mountains. Logging in Mexico and the loss of summer habitat to farming in the Midwest has been hitting the butterflies hard for years, and while this rebound is encouraging, it might still make sense to put the monarch on the Endangered Species List, as the U.S. Fish and Wildlife Service is considering.
Usually new species are formed gradually, slowly, with the right conditions and mood lighting.
Roughly 17,000 new species are found every year.
But recently we have “discovered” a new species of lizard that speciated rapidly and under unprecedented conditions.
Read about it over at The New York Times.