There have been three ways of approaching this question.
1. The human-like remains predated Adam and Eve’s creation. Hominoids died out and are unrelated to modern humans.
Strength: This idea allows a more or less literal reading of the creation record of Gen 1, 2 while at the same time attempting to reconcile it with paleontological findings.
Weakness: When first advanced in the early and mid 19th century (for example by John Thomas the founder of the Christadelphians) it seemed like a reasonable reconciliation of science and scripture. However major advances in science over the last 200 years have made this position increasingly difficult to maintain. For example, comparison of DNA sequences between human and non-human primates, including hominoids, have provided overwhelming evidence of common ancestry.
2. The hominoids are more recent than Adam.
There are two variations of this idea:
a) The palaeontology of hominoids is unsoundly based. There has been a combination of poor science in combination with persecution of anyone who points out weakness in the theory; arguments are advanced for a recent creation of the earth and even of a recent universe.
Strength: This allows a specific literal interpretation of Genesis 1, 2.
Weakness: When carefully examined, conventional scientific arguments are soundly based and the arguments for a young creation have no merit. There is strong evidence that hominoids are much older than 10,000 years, the approximate time of Adam. Many Christians who have come to realise this have become disillusioned and lost their faith. Supporting evidence for these statements is not provided here, but is not hard to find.
b) God created things with the appearance of age.
Strength: This allows a specific literal interpretation of Genesis 1, 2. It is suggested that miracles such as the turning of water into wine indicate that the miraculously provided wine was created with an apparent age. This idea is extended for example to God creating trees with apparent annual rings that God had fabricated.
Weakness: Did God deceive us by creating a young universe, but falsifying evidence of great age in many details? Here are just two examples of many possible:
a) Several different combinations of radioactive isotopes in the rocks independently indicate an age of several billion years; why would God deceive us in this way?
b) Light that reached the earth on Feb 23rd 1987 was of a supernova that occurred 168,000 years earlier. Or was this an part of an elaborate hoax by God?
It is difficult to overstate the moral problem with the idea that God has deceived us. If we cannot rely on the evidence that God has left us, then we cannot really know anything. God could have created us last Thursday at 9am with our memories built-in.
3. Hominoids share common ancestors with modern humans.
Strength: This allows for the scientific evidence as well as a valid interpretation of Gen 1, 2. There is nothing in the Old Testament to invalidate such an interpretation.
Weakness: The apostle Paul appears to have believed that no human predated Adam, and appears to base important arguments on this:
Rom 5:12 Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned
1Co 15:45 Thus it is written, “The first man Adam became a living being”; the last Adam became a life-giving spirit.
Whatever Paul may have believed or not believed regarding scientific matters is not important. There were many things that Paul did not know and are not important for the gospel message he taught. There is evidence that Paul regarded the heart as being the part of the body that controls thought:
Rom 10:9-10 because, if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. (10) For with the heart one believes and is justified, and with the mouth one confesses and is saved.
No-one today would maintain that view of anatomy that was common in ancient times. And Paul’s argument does not depend on it. Similarly whatever Paul believed (or did not believe) regarding the existence of humans before Adam is not important. The argument that Adam was the first man should be read in combination with Paul’s statement that Christ is the “last Adam”. Since Jesus was not literally the last man, nor need it be insisted that Adam was literally the first man, although there was something special about Adam and his surrender to sin just as there was something special about Christ and his overcoming of sin. Note that there can be no scientific evidence that Adam was not a real person.
There are many ways this answer could be extended, but it is long enough as it is already.