How do hominids and hominoids differ

Encounters with nature 8, textbook

Molecular biological or physiological evidence In the precipitin test (see page 114), the human-human reaction represents the maximum possible: 100%. The reaction of the anti-human serum with chimpanzee serum is weaker. In the course of evolution, chimpanzee blood and that of humans changed in relation to the potential transitional form. The reaction is much weaker in the orangutan. These results indicate that the separation of the orangutan line from the human line occurred much earlier than that of the chimpanzee line. Hominids, together with the small great apes, the gibbons, are counted among the hominoids (human-like) primates male animals; They include the half-monkeys (lemurs and loris) and the higher primates (which include the hominids, among others). “Molecular clock” Science does not agree on the number of mutations occurring in a certain time frame. The figures vary between 0.7% (115 mutations) per million years and 4% (660 mutations) per million years. Tracking maternal lineages Paternal transmission of mtDNA is very rare. Exactly how it works has not yet been researched. 72 The Descent of Humans 73 Percentage Differences in Base Pairs Among Hominids Researching the Tribal History of Humans Raising your arm back over your head (like a tennis player does when serving) is a movement that we can only perform because our ancestors used it to develop a sequence of movements that helped them survive. Few species show this ability. It is best mastered by the gibbons living in Asia. But the orangutan (Asia) and the chimpanzees, bonobos (dwarf chimpanzees) and gorillas living in Africa can also stretch their arm over the head in this special way, a behavior that originally developed while swinging in the trees. This similarity between humans and monkeys suggests a close relationship. Charles Darwin, who recognized this kinship, was massively ridiculed for this view - kinship with the apes was seen as an attack on human dignity. The African great apes - our closest relatives fossils and molecular biological or physiological evidence indicate a very close relationship between humans and the other great apes. According to current knowledge, humans are counted among the great apes, the hominids, together with the orangutan, gorilla, chimpanzee and bonobo. The African great apes are our closest relatives. The hominids are incorporated into the order of the primates. Mitochondrial DNA is better than cell nucleus DNA for creating a “molecular clock”. Examination of the DNA of monkeys and humans suggests that the human and chimpanzee lineages separated five to seven million years ago. The gorilla line split off nine to ten million years ago. For these DNA examinations, geneticists do not use the DNA from the cell nuclei, but rather the more suitable DNA from mitochondria (mtDNA; see page 79). Since it consists of only 37 genes, it is easier to study. In a certain gene segment mutations take place at relatively constant time intervals, but these remain ineffective (do not change the function of the mitochondria) and are therefore not removed by selection. The number of deviations in the mtDNA that distinguishes two species therefore reflects the length of time that has passed since the two species separated (“molecular clock”). Since the mitochondria are constantly only inherited on the maternal side, the mtDNA analysis is only used to track maternal blood lines. 5 million –7 million years 9 million –10 million years 15 million years 1.2% 1.6% 3.1% Orangutan Gorilla Human Bonobo Chimpanzee Orangutan Gorilla Human Bonobo Chimpanzee Active yourself! Research the relationships between the primates and create a rough family tree. 71 Charles Darwin as a monkey; Caricature from 1871 Workbook page 38 M 120 Evolution For testing purposes only - property of the publisher öbv

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