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May 21, 2007 · Evolutionary highlights are presented, focusing on changes affecting the sensory systems, locomotion, breathing, feeding, and reproduction in Cetacea, Sirenia, Desmostylia, and Pinnipedia. Aquatic adaptations are specifically cited, supported by data from morphological and geochemical studies.
- Mark D. Uhen
- 2007
Oct 18, 2012 · I particularly appreciated the paleoecology section, as it showed how the evolution of marine mammals was deeply intertwined with the past positions of the continents, evolution of Earth’s oceans, and with other oceanographic factors like temperature, salinity, and productivity.
- Mark D. Uhen
- muhen@gmu.edu
- 2013
People also ask
When did mammalian evolution start?
How long did it take for marine mammals to evolve?
Do marine mammals have convergent evolution?
Do marine mammals have evolutionary histories?
A review of the broad outlines of what we know about the evolution of marine mammals from their fossil record, and then a focus on three discrete case studies that highlight important ecological transitions and evolutionary transformations that have occurred over the past 50 million years.
Figure 1. Harbor seal, walrus, dugong, and right whale) The first mammals were certainly terrestrial. There is good evidence that mammals evolved from reptile-like ancestor. Therefore at some point there was a transition from terrestrial environment to an aquatic lifestyle in this group of species. How did that occur?
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- 15
- Primate Origins
- Ocean Crossings
- Rafting
- Macroevolution
Humans appeared in southern Africa between 200,000-350,000 years ago. We know we come from Africa because our genetic diversity is highest there, and there are lots of fossils of primitive humansthere. Our closest relatives, chimps and gorillas, are also native to Africa, alongside baboons and monkeys. But primates’ closest living relatives – flyin...
The idea of oceanic dispersalis central to the theory of evolution. Studying the Galapagos Islands, Darwin saw only a few tortoises, iguanas, snakes, and one small mammal, the rice rat. Further out to sea, on islands like Tahiti, were only little lizards. Darwin reasonedthat these patterns were hard to explain in terms of Creationism – in which cas...
Several primate rafting events are well established. Today, Madagascar has a diverse lemur fauna. Lemurs arrived from Africa around 20 million years ago. Since Madagascar has been an island since the time of the dinosaurs, they apparently rafted the 400 kilometre-wide Mozambique Channel. Remarkably, fossils suggestthe strange aye-aye crossed to Mad...
One of Darwin’s great insights was the idea that everyday events – small mutations, predation, competition – could slowly change species, given time. But over millions or billions of years, rare, low-probability, high-impact events – “black swan” events – also happen. Read more: Black swans and other deviations: like evolution, all scientific theor...
By Josh Davis. 0. Within just 27 years of being formally described, humans had completely eradicated a marine mammal unlike anything seen today. Steller's sea cows were extraordinary creatures. Their closest living relatives are the dugong and manatees, known collectively as the sirenians.
Jan 26, 2015 · Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and therefore represent a classic example of convergent evolution.
