______ Third One Homo Grossmont College The Ardip
hello so that the first discussion
One of the main characteristics that defines the hominin tribe are their bipedal tendencies. However, as you have noted in the readingd for this week’s assignment, not all hominins had the same bipedal capabilities. Early hominins can be defined as being at various stages of transitioning into bipedalism while much later forms are effective bipedal runners.
As new information is discovered our understanding of hominin evolution changes. For this discussion board you will have to look for new hominin related discoveries that have made the news.
I would like you to look for a news story about hominins. Make sure that the news story on hominins covers the following time frame 6 million to 1 million.
For years we have been able to analyze the fossils of extinct humans like those of Neanderthals. Their bones gave us clues to how they looked, how they lived, and how they might be related to us. In the last few years, we have been able to get a better view into these extinct species and their relationship to our species. Thanks to next generation genomic sequencing technologies, we have been able to obtain genetic data on Neanderthals, Denisovans and others that have allowed us to make direct comparisons between our species and theirs. In addition, we have been able to observe the presence of DNA from these extinct species within our own genomes which tell us that we had kids with these now extinct humans.
Comparing Neanderthal DNA to ourselves, we find that we share 99.5 percent of our DNA with them. Which means that we and Neanderthals were separated from each other for more than 500,000 years. This also means that we were genetically similar enough to be able to have offspring with each other. We see evidence of this genetic introgression, or exchange of genes, between us and Neanderthals when we look at our DNA. Interestingly, if we obtain one thousand DNA samples from our college students, we estimate that we would be able to extract at least 20% of the Neanderthal genome from them. This means that 20% of our collective nucleotide sequences are shared with Neanderthals but this doesn’t mean that 20% of our genes are Neanderthal specific genes. Of the twenty-one thousand genes that Neanderthals had, only a few dozen of their genes survive in our species today. The same holds true for Denisovans. What is more interesting is that older versions of ourselves have a tendency to have higher levels of DNA from extinct humans compared to ourselves. In other words, over the course of thousands of years we have been slowly weeding out the DNA of the other humans from our genome in favor of our genes.
One basic question that we might like to ask is why have we been losing Neanderthal and Denisovan genes over time? Also, why do we still have a significant amount of DNA segments that don’t seem to be going anywhere? The answer to this has to do with selection.
The answer to the first part of the question has to do with the fact that we were not fully genetically compatible with the other human species to begin with. Basically, to have had Neanderthal or Denisovan genes in the past meant that an individual’s level of fitness was decreased. In other words, their ability to survive and pass on their genes to the next generation was reduced.
The answer to the second question has to do with the fact that Neanderthal and Denisovan genes that remain within us have been selected for since they confer an advantage to our species.
Your task for this week is to look for information about one Neanderthal or Denisovan genetic variant that have survived within our species and to research their adaptive advantage.
In your post, discuss ONE Neanderthal or Denisovan gene variant that is currently found within our species.
Before 70,000 years ago there were a number of human species in existence. By around 35,000 years ago we were the last human species. The big question is, why did our species survive and not the other humans. What might have given us the edge? One of the biggest differences between ourselves and the other human species has to do with the cultural material that has been left behind in the archaeological record. The most characteristic elements that makes Homo sapiens artifacts different from other species has to do with their symbolic nature and the size of their sites.
From their archaeological sites, it possible to see that Homo sapiens lived in larger groups compared to Neanderthals, Denisovans or Homo floresiensis. In fact, its possible to say that our species is the only Human species that has been able to live in a large group. The big question then becomes, what allowed us to be able to live in large groups in the first place… especially because it requires cooperation with kin and with friends.
The other thing that we see is that our archaeological record becomes filled with cultural artifact that are not just functional but are also abstract in nature. For example, in the archaeological record we see that all humans were creating stone blades. What’s different about Homo sapiens is that we are not just creating stone blades like the other humans, rather we begin to decorate our stone blades with pigments. Creating art and other symbolic creations don’t seem like a big deal unless you compare ourselves to other species and then realize that we are the only ones that consistently create abstract innovations.
Your task will be to explore the importance of language and prosocial behaviors in our evolution.
View both of the following TED talks so that you can answer the discussion questions.
and that’s the assignment
Beginning in the late Miocene and into the early Pliocene, upright walking tendencies began to develop among the hominin tribe. Upright walking tendencies slowly transformed into obligate bipedalism during the pliocene within the hominin lineage. This shift in locomotor strategy is notably marked by the gradual change in arm to leg ratio that we see when comparing early and later hominins. Early hominins have short legs and very long arms while later hominins have longer legs and short arms.
Your task for this activity will be to compare and contrast the locomotor strategies of the following three hominin species: Ardipithecus ramidus, Australopithecus afarensis and Homo erectus. You will accomplish this by answering the questions below
Use the following resource for Ardipithecus (Links to an external site.) (Click)
Use the following resource for Australopithecus (Links to an external site.) (Click)
Use the following resource for Homo erectus (Links to an external site.) (Click)
Before you begin make sure to view all unit material so that you can give me informed opinions.