Totaled 3/29 Mr F

Closed

Totaled 3/20 Mr F

     Biochemistry also reveals similarities between organisms of different species. For example, the metabolism of vastly different organisms is based on the same complex biochemical compounds. The protein cytochrome c, essential for aerobic respiration, is one such universal compound. The universality of cytochrome c is evidence that all aerobic organisms probably descended from a common ancestor that used this compound for respiration. Certain blood proteins found in almost all organisms give additional evidence that these organisms descended form a common ancestor. Such biochemical compounds, including cytochrome c and blood proteins, are so complex it is unlikely that almost identical compounds would have evolved independently in widely different organisms. Further studies of cytochrome c in different species reveal variations in the amino acid sequence of this molecule. For example, the cytochrome c of monkeys and cows is more similar than the cytochrome c of monkeys and fish. Such similarities and differences suggest that monkeys and cows ate more closely related than are monkeys and fish. Scientists have similarly compared the biochemistry of universal blood proteins. Their studies reveal evidence of degrees of relatedness between different species. This evidence implies that some species share a more recent common ancestor than other species do. From such evidence scientists have inferred the evolutionary relationships between different species of organisms. 

The idea of biochemistry started with the idea of chemical evolution developed by J.B.S. Haldane, a British scientist, and his theory of chemical evolution is life transpires as the natural process of the evolution of inorganic matter. Matter on the Earth, is the same as matter that appears throughout the vast Universe. Rules of chemistry show, matter naturally tends to arrange itself and transforms through time into larger macromolecules that are the ancestors to life, they tend to combine into the molecules that will eventually arrange themselves in living cells. That is what makes up the theory of chemical evolution. In this theory time is the important factor in which the evolution process requires the most to occur. Billions of years have passed to progress us to where we are now.

In 1950s Stanley Miller a student working in Harry Urey's lab, verified the authenticity of this theory. He chose some gases: methane, ammonia, water, and hydrogen; the four essential elements and compounds for life believed to be present on the newly developed Earth. These gases were added into a big container, and administered lighting-type energy. What was discovered at the end of the experiment was unparallel; about 12% of the carbon material in the "container" had converted into an organic acid, and about 9% of that was an alpha-amino-acid. What that tells us is that chemicals evolve in a direction; it is not random molecules that are produced, but a majority of the same molecules.

There are errors with this theory. Organisms are also critically dependent upon nucleic acids, which run proteins. DNA stands for deoxyribonucleic acid, which is one of the most significant and mysterious things about the human body. DNA is how nucleic acids are put together in humans. Regrettably, precursors for DNA have not been established with this experiment.   Thats why we say that we have a hypothesis about the origen of life but the evidence does not rise to the level of a theory such as evolution.  Someday we may know but the expirements have yet to be designed & run. Mr F

(source: Biochemistry in Evolution)

This image is a lot like the work sheet that we did it class. It shows the similarites between the different species.

Biochemistry also reveals similarities between organisms of different species. For example, the metabolism of vastly different organisms is based on the same complex biochemical compounds. The protein cytochrome c, essential for aerobic respiration, is one such universal compound. The universality of cytochrome c is evidence that all aerobic organisms probably descended from a common ancestor that used this compound for respiration. Certain blood proteins found in almost all organisms give additional evidence that these organisms descended form a common ancestor. Such biochemical compounds, including cytochrome c and blood proteins, are so complex it is unlikely that almost identical compounds would have evolved independently in widely different organisms. Further studies of cytochrome c in different species reveal variations in the amino acid sequence of this molecule. For example, the cytochrome c of monkeys and cows is more similar than the cytochrome c of monkeys and fish. Such similarities and differences suggest that monkeys and cows ate more closely related than are monkeys and fish. Scientists have similarly compared the biochemistry of universal blood proteins. Their studies reveal evidence of degrees of relatedness between different species. This evidence implies that some species share a more recent common ancestor than other species do. From such evidence scientists have inferred the evolutionary relationships between different species of organisms.

The similarities described above are not the only ones scientists have noticed among organisms of different species. The image to the left shows that embryos of certain species develop almost identically, especially in the early stages. Such physical similarities indicate that there are genetic similarities between the organisms. These similarities can be considered evidence that the organisms shown probably descended from a common ancestor.

The similarities between living species-- in ancestry, in homologous and vestigial structures, in embryological development, and in biochemical compounds-- all could be explained as extremely remarkable coincidences. However, a far more probable explanation of these similarities is that species have arisen by descent and modification from more ancient forms. Additionally, the fossil record contributes compelling evidence that species have changed over time. The fossil evidence and evidence from living organisms strongly suggest that species evolve.