<h2>540 million years ago
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Paleozoic.
Era immediately follows Precambrian It lasted about 4.5 billion years.
When did abundant fossil evidence first appear in the geologic record.
540 million years ago.
Answer: Option B.
Neural crest and peripheral nervous system.
Explanation:
Neural crest are bilateral paired cells of the neural tube that arise from the ectoderm layer of the embryo. Thesescells move to different part of the body and differentiate into various cell types like melanocytes,cartilage and bone, smooth muscle, craniofacial, neurons, gangalia e.t.c. The neural crest running through neural tube develop into peripheral nervous system after birth. Peripheral nervous system consist of neurons and gangalia outside the nervous system The peripheral nervous system connect the central nervous system to organs, skin and limbs.
Answer:Species Dynamics. This theory is quite straightforward: species that can colonize new areas faster and reproduce in greater number than they become extinct have the greatest chances to thrive. The tropics offer favorable conditions for these conditions to be met.
There Is More Diversity Near the Equator. ... Another argues that more solar energy is received around the equator, allowing for greater species richness. A third points out that equatorial tropics are the largest biome, so it makes sense that there would be more species.
Explanation:
