More Perlishly:

use strict;
use warnings;
use autodie;

open my $IN,  '<', 'in.txt';
open my $OUT, '>', 'out.txt';

while ( my $line = <$IN> ) {
    print $OUT $line if $line =~ /Homo Sapiens/;
}

close $IN;
close $OUT;

__END__
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Hope this helps!

Edit: removed the chomp to print the linebreaks