also how long has "man" been around?
2006-10-12 23:56:49 · 6 answers · asked by Mr Hughes 1 in Science & Mathematics ➔ Other - Science
Continents float around with speed of the order of a few centimeter per year. That amounts to about 100 km since humanids are around, roughly the last 10 million years.
More important on that time scale is therefore the rise and fall of the sea level. In ice ages, periods when the earth is cold, a large amount of ocean water transforms into ice. The result are sea levels upto 100 meter lower. This is more than enough to connect England and Ireland to the continent of Europe, close the Bosporus, join America to Siberia, join most of the Indonesion islands to the Asian mainland and join Spain to Nord Africa.
(If the latter condition is true long enough the Mediterranean dries up: this happened last 6 million years ago.)
2006-10-13 00:43:31 · answer #1 · answered by cordefr 7 · 2⤊ 0⤋
Since Homo sapiens appeared 250,000 to 200,000 years ago there have been many changes in sea-level. For most of this time, sea-level was below what it is now, sometimes over 100m below. And at times of low sea-level, many places separated now would have been joined (250,000 years is too short a time for any significant movement of the continental plates - a few km/miles at the most).
There's a nice map here:
2006-10-13 07:34:38 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Europe and Africa is believed to have been joined at one time along with other land possibly even America, land masses are moving all the time.
2006-10-13 07:00:10 · answer #3 · answered by Anonymous · 0⤊ 1⤋
yes all the continents in fact used to be one huge super contiunent,and it broke down a long time ago,coz of the continuos shift of the earths crust that results in huge earthqakes,for examples one of the broken pieces of the super cotiunent was called urasia,and it broke down later into urope and asia,yup asia and urope,were joined long time ago also.well consirning ur second part of the question no true validated theories were proven consirning the age of humanity on planet earth,but it is estimated by about fifteen millon years.but yet it is still guesses and not yet proven.
2006-10-13 07:12:40 · answer #4 · answered by Anonymous · 0⤊ 1⤋
England was joined to France during the last ice age and that was 20,000 years ago
2006-10-13 07:08:58 · answer #5 · answered by amania_r 7 · 1⤊ 0⤋
i donno....!
2006-10-13 06:59:17 · answer #6 · answered by F1 1 · 0⤊ 1⤋