By 400,000 humans with a mix of homo erectus and homo sapien like features start to appear. their scientific name is

Homo neanderthalensis

Explanation:

Homo neanderthalensis, commonly known as Neanderthal, was a species of hominid that occurs in the fossil records around 430,000 years ago up until 40,000 years ago. This hominid lived in Europe, the Middle East, and the western half of Central Asia. The Neanderthal is a hominid that looks like a cross between the Homo sapiens and the Homo erectus. It is believed that this species of hominid was mostly carnivorous, and that the majority of the food came from hunting of animals, and much less from gathering plants. With the migration of the Homo sapiens into the territory of the Neanderthal though, its numbers started to quickly decline and it went extinct, but it left its DNA as the two species were interbreeding, so lot of people in Europe and Asia have a Neanderthal DNA, usually between 1 and 4%.

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.