Question

The ancestor of the man who first stood erect was
(a) Australopithecus
(b) Cro-magnon
(c) Java-ape man
(d) Peking man

Answer 1

Evolution is a very slow process and takes too long to complete the process. Human evolution starts from the Dryopithecus which leads to the modern-day humans called Homo sapiens. It depends upon the environmental factors.

Complete answer:
Australopithecus was the ancestor of the man who stood erect for the first time. In 1924, the Fossil of this genus was first discovered in South Africa. According to the pieces of evidence they used to live on the ground. They used stones as weapons and usually walked in an erect position. Height is up to 4 feet and weighs about 60 to 80 pounds. The males were larger in height than the males and were more in numbers, this shows sexual dimorphism among them. As their name indicates, Australis, meaning Southern and pithecus, meaning ape. Both the terms were derived from the Greek words. Their brain was around $35\%$ of the size of the now modern humans having more cranial capacity than the chimpanzees. The teeth of Australopithecus were found to be 32 and are equal to the numbers of teeth present in modern humans with much larger cheeks and jaws.

Additional information:
-Peking man was formerly known as the Sinanthropus pekinensis. They belong to the Homo erectus and considered as the pioneer of the peoples from china. Their age was estimated and was found to be around 750,000 and 300,000 years old.
-During the course of evolution, Homo erectus evolved into Homo sapiens . Homo sapiens Neanderthal and Homo sapiens sapiens were the two subspecies that were discovered. There is also a small hand. Remains of human sapiens named Cro-Magnon which was first discovered in Europe. Their jaws are reduced. Used to collect food through hunting. Art first appeared during this time.
-The java man was scientifically named Homo erectus erectus. It is known from when fossil remains were found on the island of Java and Indonesia. Their cranial capacity was around 900 cc with a small forehead, skull bones were thick, at top of head crest was present to attach tightly with the jaws and chin was absent.

Note:
The Evolution in humans is dependent upon various processes that result in the change in the structure and function of the body, these processes include mutation, chromosomal abnormalities, reproductive isolation, genetic recombination, and natural selection. The evolution of humans involves the following stages: Dryopithecus, Ramapithecus, Australopithecus, Homo erectus , Homo sapiens , and Homo sapiens sapiens.