Has the human species changed since first defined as homo sapiens sapiens?
I'm asking this question partly because I'm wondering how we might evolve next.
We continue to evolve all the time: http://www.npr.org/2013/09/27/226837803/modern-humans-still-evolving-and-faster-than-ever
For those who think the forces of natural selection no longer apply to modern humans, paleoanthropologist John Hawks would urge you to reconsider. In recent times — that's 10 to 20 thousand years, for a paleoanthropologist — Hawks says we've picked up genetic variations in skin color, and other traits that allow us to break down starch and digest cheese.
Homo sapiens sapiens is over 100,000 years old and we have changed in many ways since then, as noted in the above NPR article!
I'm not sure we can say there is a "first" homo sapiens sapiens -- the change from one species to another is gradual. You may know that mixing red and blue gives purple, but at what points do we officially have red, purple, or blue when mixing different levels of red and blue?
There is certainly some evolution. Take, for example, lactose tolerance. It's a relatively new mutation that happened less than 8000 years ago. Yes, basically all humans in the stone age were lactose intolerant. The change started to be common after humans defeloped argriculture on a big scale and is still less common in some groups than in others even today.
As another example, our jaws have become smaller and now we get trouble with the amount of teeth that hasn't changed since the first modern humans developed. Some people don't have wisdom teeth, that is part of the evolutionary answer to that.
Also people have become bigger since the early days.
I can't assure how humans will develop in the future, but even smaller jaws, weaker limbs (due to more dependence on technology and less use of personal strength) and longer fingers (because presicion is more important nowadays than raw power) might be some factors. Also with the increase of modern globalization, humans might become less diverse in appearance.
An additional question is, are we evolving in a positive or negative way stronger vs weaker.
That would depend on what you consider week or strong. All evolution really cares about is how many babies do you successful raise to adulthood.
You may be the strongest, smartest and most handsome man in the world. But at the end of the day, if you do not have children you are a failure.
So are we evolving better... here is something to think about. The BRCA mutation that causes breast cancer in women... also causes increase fertility in women. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4457526/ So is that good or bad? Bad for the individual.... but good for evolution. More children.
Or how about muscle strength... humans muscle strength per body weight is terrible compared to every other ape. The average chimp is half the weight of a man and 6 times stronger. So humans are weak.... well we can pick up and sewing needle and tread that needle but a chimp can't. In human evolution we have sacrificed strength for dexterity. So is this good or bad. Strong or week?
Answering the first question. Yes we have. Human evolved in africa. The most ancient population are in africa. All those strange looking non-africans are the produces of evolution in the past 60,000 years. Those moving northwards became paler. And developed longer hair. Mutations resulted in lost of eye pigments 5000yr ago resulting in green then later blue eyes. (Terrible in the savannah of africa but meh in Europe)
Also some evolution occurred in receptors targeted by viruses. So better immunity. Think the black plague 60% death in Europe and Smallpox in Americas, 90-95% death rate.