The love of horses in people runs deep with the people who know them and one of the all-time biggest hits on Ithaka was about the overall evolution of the Eohippus line since the fossil record is one of the best and most complete for any any line of animals. (Ithaka: Evolution of Eohippus (Horse))
Eohippus started out as not much larger than a big dog but look at him today. This sequence was long after the Permian Extinction mentioned yesterday as there wasn't anything on land much bigger than a chipmunk after that and mammals were nowhere to be seen. (Ithaka: The Permian Extinction and the Relation to Modern Times)
The previous article on Eohippus considered the overall evolution and, in a gentle way, that religion and science don't necessarily preclude or obviate each other. For most articles, it's great if they get a couple of hundred hits but that one got over three thousand and is still climbing.
The current research is regarding what drove the evolution. The previous article showed the course of the evolution but didn't go into any of the factors influencing it so that brings us to the current interest. (Science Daily: Climate change responsible for the great diversity in horses)
Credit: MAURICIO ANTÓN
- SD
The former case for evolutionary drivers:
Their conclusions challenge a classic theory, which links the evolutionary success of horses to several novel adaptations in response to the spread of grasslands around 18 million years ago. "According to the classic view, horses would have evolved faster in when grasslands appeared, developing teeth that were more resistant to the stronger wear that comes with a grass-dominated diet. They also became bigger to more effectively digest this low quality food, and as a strategy against predators in these new, open habitats", explains Juan L. Cantalapiedra, researcher at the Museum für Naturkunde in Berlin, Germany.
- SD
The current case for a different way evolution worked:
But did teeth and body size indeed evolve that fast? It seems they didn't. According to the new results, these evolutionary changes could have been much slower than previously assumed. In fact, Cantalapiedra and colleagues were able to show that all these newly evolved species of horses were ecologically very similar. Thus, rather than a multiplication of ecological roles, the new results point to external factors, such as increasing environmental heterogeneity, as the main evolutionary force.
- SD
Ed: that sounds kind of thin. Lotta words but not much proof.
Roger that.
Diversification accelerated again two more times, "when changes in sea level allowed their migration from North America into Eurasia and Africa, 11 and 4 million years ago", explains María Teresa Alberdi, at the National Museum of Natural Sciences in Madrid. "Then, again, new species appeared very fast, but without showing dramatic changes in appearance", concludes Cantalapiedra.
- SD
Frankly, mates, I don't see the case stated all that well. There's enough to see the case exists so likely the next round of research will be going into genomic studies since they can manage astonishing accuracy that way.
Ed: why publish this when it seems vague?
We see enough to know the original case for explaining equine evolution doesn't really get it done. The explanation for what did do it is vague but the answer to that is investigate more. The best science may answer some questions but it will create a whole lot more of them.
Eohippus started out as not much larger than a big dog but look at him today. This sequence was long after the Permian Extinction mentioned yesterday as there wasn't anything on land much bigger than a chipmunk after that and mammals were nowhere to be seen. (Ithaka: The Permian Extinction and the Relation to Modern Times)
The previous article on Eohippus considered the overall evolution and, in a gentle way, that religion and science don't necessarily preclude or obviate each other. For most articles, it's great if they get a couple of hundred hits but that one got over three thousand and is still climbing.
The current research is regarding what drove the evolution. The previous article showed the course of the evolution but didn't go into any of the factors influencing it so that brings us to the current interest. (Science Daily: Climate change responsible for the great diversity in horses)
Three species of Hipparion, that lived in the Iberian peninsula between 9 million years and 5 million years ago.
Credit: MAURICIO ANTÓN
- SD
The former case for evolutionary drivers:
Their conclusions challenge a classic theory, which links the evolutionary success of horses to several novel adaptations in response to the spread of grasslands around 18 million years ago. "According to the classic view, horses would have evolved faster in when grasslands appeared, developing teeth that were more resistant to the stronger wear that comes with a grass-dominated diet. They also became bigger to more effectively digest this low quality food, and as a strategy against predators in these new, open habitats", explains Juan L. Cantalapiedra, researcher at the Museum für Naturkunde in Berlin, Germany.
- SD
The current case for a different way evolution worked:
But did teeth and body size indeed evolve that fast? It seems they didn't. According to the new results, these evolutionary changes could have been much slower than previously assumed. In fact, Cantalapiedra and colleagues were able to show that all these newly evolved species of horses were ecologically very similar. Thus, rather than a multiplication of ecological roles, the new results point to external factors, such as increasing environmental heterogeneity, as the main evolutionary force.
- SD
Ed: that sounds kind of thin. Lotta words but not much proof.
Roger that.
Diversification accelerated again two more times, "when changes in sea level allowed their migration from North America into Eurasia and Africa, 11 and 4 million years ago", explains María Teresa Alberdi, at the National Museum of Natural Sciences in Madrid. "Then, again, new species appeared very fast, but without showing dramatic changes in appearance", concludes Cantalapiedra.
- SD
Frankly, mates, I don't see the case stated all that well. There's enough to see the case exists so likely the next round of research will be going into genomic studies since they can manage astonishing accuracy that way.
Ed: why publish this when it seems vague?
We see enough to know the original case for explaining equine evolution doesn't really get it done. The explanation for what did do it is vague but the answer to that is investigate more. The best science may answer some questions but it will create a whole lot more of them.
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