The body is a thing that can be hurt or killed. Its functions are stopped by death.
Study of the human body[change | change source]
Some people study the human body. They look at where it is different from or the same as other animals' bodies. These animals can be alive today. Or they can be extinct animals like other hominids. (Hominids are primates that are close to humans. Neanderthals and Homo erectus were hominids.) Some people study how the human body works and lives in its environment. Some people study what people think about their body. Artists study how to draw or paint the human body.
Fields of study[change | change source]
Many different fields of study look at the human:
- Biology is a field of science. It studies living things. It looks at how the human body works. It studies how the human body came from evolution. It studies how genetics makes the human body.
- Anthropology is a field of science. It compares humans to other hominids. It also studies all other hominid bodies. They look at how humans and chimpanzees are the same or different.
- Psychology is a field of medicine. It looks at how people think and feel. The brain is part of the body. How we think and feel comes from the brain. So psychologists study the body. They study how the brain lets us be who we are.
- Religion also talks about the body. Some religions see the body as where the soul lives. Some see the body as like a church. This is because a church is where people worship God. These people think God should be worshiped inside people. Some religions think the body is made from chakras that connect us to the universe.
- Medicine sees the body like a machine. Doctors want to fix problems with the body. They study how to fix the problems, called diseases.
The human body and other animals[change | change source]
Scientists think that the human body is very much like other animals. They see that some human behaviors are like animal behaviors. (Behaviors are the way an organism acts.) They know that 98% of the DNA in humans is the same as other primates.
DNA sequence differences between humans and chimpanzees[change | change source]
The animal that is alive now that is closest to humans is the chimpanzee. 98.4% of the DNA is the same between humans and chimpanzees. However, this applies only to single nucleotide polymorphisms, that is, changes in single base pairs only. The full picture is rather different.
The draft sequence of the common chimpanzee genome was published in 2005. It showed that the regions which are similar enough to be aligned with one another account for 2400 million of the human genome’s 3164.7 million bases, that is, 75.8% of the genome.
This 75.8% of the human genome is 1.23% different from the chimpanzee genome in single-nucleotide polymorphisms (SNPs - changes of single DNA “letters” in the genome). Another type of difference, called 'indels' (insertions/deletions) account for another ~3% difference between the alignable sequences. In addition, variation in copy number of large segments (> 20 kb) of similar DNA sequence provides a further 2.7% difference between the two species. Hence the total similarity of the genomes could be as low as about 70%.
References[change | change source]
- The Chimpanzee Sequencing and Analysis Consortium (2005). "Initial sequence of the chimpanzee genome and comparison with the human genome". Nature 437 (1 September 2005): 69–87. doi:10.1038/nature04072. PMID 16136131.
- Cheng Z. et al. (2005). "A genome-wide comparison of recent chimpanzee and human segmental duplications". Nature 437 (1 September 2005): 88–93. doi:10.1038/nature04000. PMID 16136132.