The ship and its origin cannot be traced with any accuracy now (partly because too many of the human splinters in the galaxy want to claim it was theirs, and partly because of records lost during the Lyran wars and other discontinuities. The ship itself has never been found. Only this much is known from the few clear images that have been retrieved by quantum fencing techniques and observations at 1.5 million light years out from Earth (necessarily a tad fuzzy.) Genetic sampling of the present generations tell us that at least seven females survived the crash and went on the procreate. The number of males that survived cannot be determined, the human genome being inherently matrilineal.
Physically the human body is a brilliant compromise -- capable of anything, yet specialized at nothing -- perhaps one of the most generalized of all body types currently extant in the galaxy. (That does not mean better than Saurian, Avian, Cetacean, synthetic or any of the main-stream variations on bodies; just more generalized. As even the humans say, it isn't what you have, but what you do with it that matters.) Earth humans have the standard two legs, and two arms, two eyes and two ears arranged on a bilateral symmetry. Two brain hemispheres with an interesting neurological cross over (left brain wired to right side of the body and vice-versa).
The ED Human is covered in a smooth skin, with little texturing to it, no scales, ridges or patterning, except in cases of disease or "disfigurement." There is a minor variation in texture, ranging from silky smooth to mildly textured, typically increasing with age. "Wrinkled skin" is viewed with extreme disfavor. There is minor variation in coloring, ranging from mildly pale, to tan, to mahogany, sometimes with a barely discernable tint. There are no green, cyan, orange, blue or purple variations, though all are allowed for by the genome itself. Nor are there any patterns, or complex markings, unlike most of the other mammalian life forms on the planet. Apparently this difference from true native earth life has gone unnoticed by the ED humans themselves. They have invested a wholly disproportionate amount of energy and meaning to these wholly minor variations of skin, actually splitting themselves into sub-species socially, politically and economically based on "color". Given that all human skin is a variation of the same color, this may be a very difficult concept for visitors to understand.
ED Humans also have the typical two nostrils leading into a single cavity in the skull -- which should be a serious clue to any one owning one of these things, but it never seems to have occurred to Earthlings that the structure of two nostrils leading into a single nasal cavity serves no purely physical purpose. But it also seems to have never occurred to them that everything in, of or about their bodies has a purpose, that nothing is superfluous, random or obsolete. In other words (strange as this might seem) ED Humans really have no awareness at all of either the spiritual or symbolic qualities of their own bodies, of the energetic components of their bodies, that "spiritual" and "conscious" are synonymous concepts or of what it means for a being to inhabit a body. In fact, they believe they are their bodies! Not a single of their main-stream religions teaches them otherwise (though there are some minority religions that do understand bits and pieces of the truth).
This is the single most significant variation between ED Humans and other humanoid races, this rigid, deep and unshakable belief they have that they actually are their bodies. No matter how many times they have "lived a life time" it is always with a total amnesia of these other "life times" so long as they are in a body. Once out of the current body, memory tends to return, but the condition is so "unfamiliar" and disorienting, that their chances of actually operating in the natural state is virtually zero. So, bottom line, ED Humanity is completely dominated by a "meat body" mentality. Some of this is due to damage done to the human genome, and some of it is other debris left over from the varied and contested history humans have endured during their residence on the planet, wash over from the wars and politics of the deep past.
This body identification is crucial in understanding the complexities of Earth's present societies, politics, economics and paths of development. It imposes a very strange set of limitations that they run on each other and mutually reinforce at every moment. It is the crucial limiting factor on the ED humans, so that, poised as they are for (re)entry into galactic civilization (within the next hundred years, even, unless the Dracs or Greys win out first), unless they regain their spiritual identities as true individuals, their admittance into civilization may have to be delayed.
Another very important characteristic is the 24,000 year cycle that alternates the planet closer to then away from the galactic core, due to Sol's orbit around a dark companion. At least two things this causes is a (slight) variation in distance from the galactic core, as well as a change in the background particle and energy density that the planet is currently swimming through. Both of these naturally have an effect on the level of functioning of the human brain -- alternating it higher when closer to the core, and lower when farther from. The humanoid brain, being a fine quantum machine, is sensitive to both factors.
In depth analysis of both these factors (and others that previal on earth), and how these factors are used -- for and against the Earthlings -- can be found in the ETsOnly! library.
During your visit to the Earth and while interacting with Earthlings -- whatever your purpose here -- you will find it wise to be familiar with how the function and why they function the way they do. Otherwise you may buzz off later, shaking your head and wondering what all the hooraw is about.