Time- Evolutionary change- few gen Speciation- thousands of years
The likeness and the variation in comparative anatomy is different in the anatomy of species.
A noteworthy issue in deciding evolutionary connections in view of near life structures. Look at wings. Wings are presented in various forms of life. Birds, bats and insects all have wings, what does this say in regards to how firmly related they are? It is enticing to say that the gatherings more had a typical winged ancestor. This is wrong. The wings of bats and birds are both gotten from the forelimb of a typical, …show more content…
In the wake of starting to expand from cocoa bears, the polar bear's progenitors experienced a progression of developmental changes keeping in mind the end goal to make due in the Arctic. The bears adjusted to an existence of chasing seals and surviving amazing icy. A standout amongst the most amazing adjustments was the capacity to flourish with a fat-rich eating regimen without evident heart harm.
Protection. Two layers of hide and a thick layer of muscle to fat quotients give polar bears such fantastic protection that their body temperature and metabolic rate won't change notwithstanding when temperatures reach - 34º F. Conservative ears and a little tail additionally avert heat misfortune. A polar bear's body temperature is 98.6º F—normal for well evolved creatures.
On sharply cool days with wild winds, polar bears delve cover pits in snow banks and twist up in a tight ball. Infrequently they cover their gags, which transmit heat, with their thickly furred paws and permit the snow to float around and over