Human evolution
Human evolution is the lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years.
One of the earliest defining human traits, bipedalism -- the ability to walk on two legs -- evolved over 4 million years ago. Other important human characteristics -- such as a large and complex brain, the ability to make and use tools, and the capacity for language -- developed more recently. Many advanced traits -- including complex symbolic expression, art, and elaborate cultural diversity -- emerged mainly during the past 100,000 years.
Humans are primates. Physical and genetic similarities show that the modern human species, Homo sapiens, has a very close relationship to another group of primate species, the apes. Humans and the great apes (large apes) of Africa -- chimpanzees (including bonobos, or so-called “pygmy chimpanzees”) and gorillas -- share a common ancestor that lived between 8 and 6 million years ago. Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa.
Most scientists currently recognize some 15 to 20 different species of early humans. Scientists do not all agree, however, about how these species are related or which ones simply died out. Many early human species -- certainly the majority of them – left no living descendants. Scientists also debate over how to identify and classify particular species of early humans, and about what factors influenced the evolution and extinction of each species.
Early humans first migrated out of Africa into Asia probably between 2 million and 1.8 million years ago. They entered Europe somewhat later, between 1.5 million and 1 million years. Species of modern humans populated many parts of the world much later. For instance, people first came to Australia probably within the past 60,000 years and to the Americas within the past 30,000 years or so. The beginnings of agriculture and the rise of the first civilizations occurred within the past 12,000 years.
Hope this helps:)
It all depends on the trait. If the dominant is more common that the recessive trait then it is more likely to a dominant trait in the gene pool. But if the recessive trait is more common in the gene pool then you will have a recessive trait. Does this make sense? Let me know if I'm right!
Answer:
the guy who is type O
Explanation:
using a punnet square you can come up with 4 seperate possiblitys for the baby's blood type. We don't know any of their recessive traits tho so im pretty sure its O. i could be wrong tho!
The answer is D) 1/2.
Let's imagine that two genes of the genotype can be analysed separately.
Black fur is determined by dominant allele B. In this case, parents Bb and BB will give offspring with only brown fur:
Parents: Bb x BB
Offspring: BB BB Bb Bb
Both homozygous (BB) and heterozygous (Bb) offspring will have black fur.
On the other hand, long tails are determined by recessive allele t. Parents Tt and tt will have 50% offspring with short tail and 50% offspring with long tail:
Parents: Tt x tt
Offspring: Tt Tt tt tt
Heterozygous offspring (Tt) will have short tail, and homozygous offspring (tt) will have a long tail.
So, the offspring will definitely have black fur and will not affect the fraction of the offspring with black fur and long tails from the cross of <span>BbTt × BBtt. But, </span>there will be 2 out of 4 offspring with short tails which is 50% or 1/2.
