In this phylogeny feather pattern on the head is the trait used to separate the sparrows into groups. dna analysis suggests a different phylogeny that places white-crowned birds and golden-crowned birds more closely together. therefore, what process results in the striped pattern on the head is result

Convergent evolution

Explanation:

Convergent evolution occurs when living beings develop characteristics that perform the same function but have different origins, such as insect wings and bird wings. These, although they play similar roles, are not derived from the same structures present in a unique common ancestor between these two species. Thus, evolutionary adaptation to similar ways of life leads unrelated organisms to develop similar forms, a phenomenon called convergent evolution.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!