dnacomp: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/lib/phylip/bin/dnacomp - from package: phylip

You may install the required package with command apt-get install {package}
Error in other languages:
dnacomp: bevel nie gevind nie
dnacomp: comandă negăsită
dnacomp: comando não encontrado
dnacomp: commande introuvable
dnacomp: command not found
dnacomp: käsku ei ole
dnacomp: không tìm thấy lệnh
dnacomp: komanda nerasta
dnacomp: Kommando nicht gefunden.
dnacomp: kommandot finns inte
dnacomp: komut yok
dnacomp: nie znaleziono polecenia
dnacomp: níor aimsíodh an t-ordú
dnacomp: no se encontró la orden
dnacomp: no s'ha trobat l'ordre
dnacomp: opdracht niet gevonden
dnacomp: parancs nem található
dnacomp: perintah tidak ditemukan
dnacomp: príkaz nenájdený
dnacomp: příkaz nenalezen
dnacomp: команда не найдена
dnacomp: командата не е открита
dnacomp: 命令找不到
dnacomp: コマンドが見つかりません